src/kitemviews/kitemlistview.cpp

   1 /*
   2  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
   3  *
   4  * Based on the Itemviews NG project from Trolltech Labs
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #include "kitemlistview.h"
  10
  11 #ifndef QT_NO_ACCESSIBILITY
  12 #include "accessibility/kitemlistcontaineraccessible.h"
  13 #include "accessibility/kitemlistdelegateaccessible.h"
  14 #include "accessibility/kitemlistviewaccessible.h"
  15 #endif
  16 #include "dolphindebug.h"
  17 #include "kitemlistcontainer.h"
  18 #include "kitemlistcontroller.h"
  19 #include "kitemlistheader.h"
  20 #include "kitemlistselectionmanager.h"
  21 #include "kstandarditemlistwidget.h"
  22
  23 #include "private/kitemlistheaderwidget.h"
  24 #include "private/kitemlistrubberband.h"
  25 #include "private/kitemlistsizehintresolver.h"
  26 #include "private/kitemlistviewlayouter.h"
  27
  28 #include <QElapsedTimer>
  29 #include <QGraphicsSceneMouseEvent>
  30 #include <QGraphicsView>
  31 #include <QPropertyAnimation>
  32 #include <QStyleOptionRubberBand>
  33 #include <QTimer>
  34 #include <QVariantAnimation>
  35
  36 namespace
  37 {
  38 // Time in ms until reaching the autoscroll margin triggers
  39 // an initial autoscrolling
  40 const int InitialAutoScrollDelay = 700;
  41
  42 // Delay in ms for triggering the next autoscroll
  43 const int RepeatingAutoScrollDelay = 1000 / 60;
  44
  45 // Copied from the Kirigami.Units.shortDuration
  46 const int RubberFadeSpeed = 150;
  47
  48 const char *RubberPropertyName = "_kitemviews_rubberBandPosition";
  49 }
  50
  51 #ifndef QT_NO_ACCESSIBILITY
  52 QAccessibleInterface *accessibleInterfaceFactory(const QString &key, QObject *object)
  53 {
  54     Q_UNUSED(key)
  55
  56     if (KItemListContainer *container = qobject_cast<KItemListContainer *>(object)) {
  57         if (auto controller = container->controller(); controller) {
  58             if (KItemListView *view = controller->view(); view && view->accessibleParent()) {
  59                 return view->accessibleParent();
  60             }
  61         }
  62         return new KItemListContainerAccessible(container);
  63     } else if (KItemListView *view = qobject_cast<KItemListView *>(object)) {
  64         return new KItemListViewAccessible(view, view->accessibleParent());
  65     }
  66
  67     return nullptr;
  68 }
  69 #endif
  70
  71 KItemListView::KItemListView(QGraphicsWidget *parent)
  72     : QGraphicsWidget(parent)
  73     , m_enabledSelectionToggles(false)
  74     , m_grouped(false)
  75     , m_highlightEntireRow(false)
  76     , m_alternateBackgrounds(false)
  77     , m_supportsItemExpanding(false)
  78     , m_editingRole(false)
  79     , m_activeTransactions(0)
  80     , m_endTransactionAnimationHint(Animation)
  81     , m_itemSize()
  82     , m_controller(nullptr)
  83     , m_model(nullptr)
  84     , m_visibleRoles()
  85     , m_widgetCreator(nullptr)
  86     , m_groupHeaderCreator(nullptr)
  87     , m_styleOption()
  88     , m_visibleItems()
  89     , m_visibleGroups()
  90     , m_visibleCells()
  91     , m_scrollBarExtent(0)
  92     , m_layouter(nullptr)
  93     , m_animation(nullptr)
  94     , m_oldScrollOffset(0)
  95     , m_oldMaximumScrollOffset(0)
  96     , m_oldItemOffset(0)
  97     , m_oldMaximumItemOffset(0)
  98     , m_skipAutoScrollForRubberBand(false)
  99     , m_rubberBand(nullptr)
 100     , m_tapAndHoldIndicator(nullptr)
 101     , m_mousePos()
 102     , m_autoScrollIncrement(0)
 103     , m_autoScrollTimer(nullptr)
 104     , m_header(nullptr)
 105     , m_headerWidget(nullptr)
 106     , m_indicatorAnimation(nullptr)
 107     , m_dropIndicator()
 108     , m_sizeHintResolver(nullptr)
 109 {
 110     setAcceptHoverEvents(true);
 111     setAcceptTouchEvents(true);
 112
 113     m_sizeHintResolver = new KItemListSizeHintResolver(this);
 114
 115     m_layouter = new KItemListViewLayouter(m_sizeHintResolver, this);
 116
 117     m_animation = new KItemListViewAnimation(this);
 118     connect(m_animation, &KItemListViewAnimation::finished, this, &KItemListView::slotAnimationFinished);
 119
 120     m_rubberBand = new KItemListRubberBand(this);
 121     connect(m_rubberBand, &KItemListRubberBand::activationChanged, this, &KItemListView::slotRubberBandActivationChanged);
 122
 123     m_tapAndHoldIndicator = new KItemListRubberBand(this);
 124     m_indicatorAnimation = new QPropertyAnimation(m_tapAndHoldIndicator, "endPosition", this);
 125     connect(m_tapAndHoldIndicator, &KItemListRubberBand::activationChanged, this, [this](bool active) {
 126         if (active) {
 127             m_indicatorAnimation->setDuration(150);
 128             m_indicatorAnimation->setStartValue(QPointF(1, 1));
 129             m_indicatorAnimation->setEndValue(QPointF(40, 40));
 130             m_indicatorAnimation->start();
 131         }
 132         update();
 133     });
 134     connect(m_tapAndHoldIndicator, &KItemListRubberBand::endPositionChanged, this, [this]() {
 135         if (m_tapAndHoldIndicator->isActive()) {
 136             update();
 137         }
 138     });
 139
 140     m_headerWidget = new KItemListHeaderWidget(this);
 141     m_headerWidget->setVisible(false);
 142
 143     m_header = new KItemListHeader(this);
 144
 145 #ifndef QT_NO_ACCESSIBILITY
 146     QAccessible::installFactory(accessibleInterfaceFactory);
 147 #endif
 148 }
 149
 150 KItemListView::~KItemListView()
 151 {
 152     // The group headers are children of the widgets created by
 153     // widgetCreator(). So it is mandatory to delete the group headers
 154     // first.
 155     delete m_groupHeaderCreator;
 156     m_groupHeaderCreator = nullptr;
 157
 158     delete m_widgetCreator;
 159     m_widgetCreator = nullptr;
 160
 161     delete m_sizeHintResolver;
 162     m_sizeHintResolver = nullptr;
 163 }
 164
 165 void KItemListView::setScrollOffset(qreal offset)
 166 {
 167     if (offset < 0) {
 168         offset = 0;
 169     }
 170
 171     const qreal previousOffset = m_layouter->scrollOffset();
 172     if (offset == previousOffset) {
 173         return;
 174     }
 175
 176     m_layouter->setScrollOffset(offset);
 177     m_animation->setScrollOffset(offset);
 178
 179     // Don't check whether the m_layoutTimer is active: Changing the
 180     // scroll offset must always trigger a synchronous layout, otherwise
 181     // the smooth-scrolling might get jerky.
 182     doLayout(NoAnimation);
 183     onScrollOffsetChanged(offset, previousOffset);
 184 }
 185
 186 qreal KItemListView::scrollOffset() const
 187 {
 188     return m_layouter->scrollOffset();
 189 }
 190
 191 qreal KItemListView::maximumScrollOffset() const
 192 {
 193     return m_layouter->maximumScrollOffset();
 194 }
 195
 196 void KItemListView::setItemOffset(qreal offset)
 197 {
 198     if (m_layouter->itemOffset() == offset) {
 199         return;
 200     }
 201
 202     m_layouter->setItemOffset(offset);
 203     if (m_headerWidget->isVisible()) {
 204         m_headerWidget->setOffset(offset);
 205     }
 206
 207     // Don't check whether the m_layoutTimer is active: Changing the
 208     // item offset must always trigger a synchronous layout, otherwise
 209     // the smooth-scrolling might get jerky.
 210     doLayout(NoAnimation);
 211 }
 212
 213 qreal KItemListView::itemOffset() const
 214 {
 215     return m_layouter->itemOffset();
 216 }
 217
 218 qreal KItemListView::maximumItemOffset() const
 219 {
 220     return m_layouter->maximumItemOffset();
 221 }
 222
 223 int KItemListView::maximumVisibleItems() const
 224 {
 225     return m_layouter->maximumVisibleItems();
 226 }
 227
 228 void KItemListView::setVisibleRoles(const QList<QByteArray> &roles)
 229 {
 230     const QList<QByteArray> previousRoles = m_visibleRoles;
 231     m_visibleRoles = roles;
 232     onVisibleRolesChanged(roles, previousRoles);
 233
 234     m_sizeHintResolver->clearCache();
 235     m_layouter->markAsDirty();
 236
 237     if (m_itemSize.isEmpty()) {
 238         m_headerWidget->setColumns(roles);
 239         updatePreferredColumnWidths();
 240         if (!m_headerWidget->automaticColumnResizing()) {
 241             // The column-width of new roles are still 0. Apply the preferred
 242             // column-width as default with.
 243             for (const QByteArray &role : std::as_const(m_visibleRoles)) {
 244                 if (m_headerWidget->columnWidth(role) == 0) {
 245                     const qreal width = m_headerWidget->preferredColumnWidth(role);
 246                     m_headerWidget->setColumnWidth(role, width);
 247                 }
 248             }
 249
 250             applyColumnWidthsFromHeader();
 251         }
 252     }
 253
 254     const bool alternateBackgroundsChanged =
 255         m_itemSize.isEmpty() && ((roles.count() > 1 && previousRoles.count() <= 1) || (roles.count() <= 1 && previousRoles.count() > 1));
 256
 257     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 258     while (it.hasNext()) {
 259         it.next();
 260         KItemListWidget *widget = it.value();
 261         widget->setVisibleRoles(roles);
 262         if (alternateBackgroundsChanged) {
 263             updateAlternateBackgroundForWidget(widget);
 264         }
 265     }
 266
 267     doLayout(NoAnimation);
 268 }
 269
 270 QList<QByteArray> KItemListView::visibleRoles() const
 271 {
 272     return m_visibleRoles;
 273 }
 274
 275 void KItemListView::setAutoScroll(bool enabled)
 276 {
 277     if (enabled && !m_autoScrollTimer) {
 278         m_autoScrollTimer = new QTimer(this);
 279         m_autoScrollTimer->setSingleShot(true);
 280         connect(m_autoScrollTimer, &QTimer::timeout, this, &KItemListView::triggerAutoScrolling);
 281         m_autoScrollTimer->start(InitialAutoScrollDelay);
 282     } else if (!enabled && m_autoScrollTimer) {
 283         delete m_autoScrollTimer;
 284         m_autoScrollTimer = nullptr;
 285     }
 286 }
 287
 288 bool KItemListView::autoScroll() const
 289 {
 290     return m_autoScrollTimer != nullptr;
 291 }
 292
 293 void KItemListView::setEnabledSelectionToggles(bool enabled)
 294 {
 295     if (m_enabledSelectionToggles != enabled) {
 296         m_enabledSelectionToggles = enabled;
 297
 298         QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 299         while (it.hasNext()) {
 300             it.next();
 301             it.value()->setEnabledSelectionToggle(enabled);
 302         }
 303     }
 304 }
 305
 306 bool KItemListView::enabledSelectionToggles() const
 307 {
 308     return m_enabledSelectionToggles;
 309 }
 310
 311 KItemListController *KItemListView::controller() const
 312 {
 313     return m_controller;
 314 }
 315
 316 KItemModelBase *KItemListView::model() const
 317 {
 318     return m_model;
 319 }
 320
 321 void KItemListView::setWidgetCreator(KItemListWidgetCreatorBase *widgetCreator)
 322 {
 323     delete m_widgetCreator;
 324     m_widgetCreator = widgetCreator;
 325 }
 326
 327 KItemListWidgetCreatorBase *KItemListView::widgetCreator() const
 328 {
 329     if (!m_widgetCreator) {
 330         m_widgetCreator = defaultWidgetCreator();
 331     }
 332     return m_widgetCreator;
 333 }
 334
 335 void KItemListView::setGroupHeaderCreator(KItemListGroupHeaderCreatorBase *groupHeaderCreator)
 336 {
 337     delete m_groupHeaderCreator;
 338     m_groupHeaderCreator = groupHeaderCreator;
 339 }
 340
 341 KItemListGroupHeaderCreatorBase *KItemListView::groupHeaderCreator() const
 342 {
 343     if (!m_groupHeaderCreator) {
 344         m_groupHeaderCreator = defaultGroupHeaderCreator();
 345     }
 346     return m_groupHeaderCreator;
 347 }
 348
 349 #ifndef QT_NO_ACCESSIBILITY
 350 void KItemListView::setAccessibleParentsObject(KItemListContainer *accessibleParentsObject)
 351 {
 352     Q_ASSERT(!m_accessibleParent);
 353     m_accessibleParent = new KItemListContainerAccessible(accessibleParentsObject);
 354 }
 355 KItemListContainerAccessible *KItemListView::accessibleParent()
 356 {
 357     Q_CHECK_PTR(m_accessibleParent); // We always want the accessibility tree/hierarchy to be complete.
 358     return m_accessibleParent;
 359 }
 360 #endif
 361
 362 QSizeF KItemListView::itemSize() const
 363 {
 364     return m_itemSize;
 365 }
 366
 367 const KItemListStyleOption &KItemListView::styleOption() const
 368 {
 369     return m_styleOption;
 370 }
 371
 372 void KItemListView::setGeometry(const QRectF &rect)
 373 {
 374     QGraphicsWidget::setGeometry(rect);
 375
 376     if (!m_model) {
 377         return;
 378     }
 379
 380     const QSizeF newSize = rect.size();
 381     if (m_itemSize.isEmpty()) {
 382         m_headerWidget->resize(rect.width(), m_headerWidget->size().height());
 383         if (m_headerWidget->automaticColumnResizing()) {
 384             applyAutomaticColumnWidths();
 385         } else {
 386             const qreal requiredWidth = columnWidthsSum() + 2 * m_headerWidget->sidePadding();
 387             const QSizeF dynamicItemSize(qMax(newSize.width(), requiredWidth), m_itemSize.height());
 388             m_layouter->setItemSize(dynamicItemSize);
 389         }
 390     }
 391
 392     m_layouter->setSize(newSize);
 393     // We don't animate the moving of the items here because
 394     // it would look like the items are slow to find their position.
 395     doLayout(NoAnimation);
 396 }
 397
 398 qreal KItemListView::verticalPageStep() const
 399 {
 400     qreal headerHeight = 0;
 401     if (m_headerWidget->isVisible()) {
 402         headerHeight = m_headerWidget->size().height();
 403     }
 404     return size().height() - headerHeight;
 405 }
 406
 407 std::optional<int> KItemListView::itemAt(const QPointF &pos) const
 408 {
 409     if (headerBoundaries().contains(pos)) {
 410         return std::nullopt;
 411     }
 412
 413     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 414     while (it.hasNext()) {
 415         it.next();
 416
 417         const KItemListWidget *widget = it.value();
 418         const QPointF mappedPos = widget->mapFromItem(this, pos);
 419         if (widget->contains(mappedPos) || widget->selectionRect().contains(mappedPos)) {
 420             return it.key();
 421         }
 422     }
 423
 424     return std::nullopt;
 425 }
 426
 427 bool KItemListView::isAboveSelectionToggle(int index, const QPointF &pos) const
 428 {
 429     if (!m_enabledSelectionToggles) {
 430         return false;
 431     }
 432
 433     const KItemListWidget *widget = m_visibleItems.value(index);
 434     if (widget) {
 435         const QRectF selectionToggleRect = widget->selectionToggleRect();
 436         if (!selectionToggleRect.isEmpty()) {
 437             const QPointF mappedPos = widget->mapFromItem(this, pos);
 438             return selectionToggleRect.contains(mappedPos);
 439         }
 440     }
 441     return false;
 442 }
 443
 444 bool KItemListView::isAboveExpansionToggle(int index, const QPointF &pos) const
 445 {
 446     const KItemListWidget *widget = m_visibleItems.value(index);
 447     if (widget) {
 448         const QRectF expansionToggleRect = widget->expansionToggleRect();
 449         if (!expansionToggleRect.isEmpty()) {
 450             const QPointF mappedPos = widget->mapFromItem(this, pos);
 451             return expansionToggleRect.contains(mappedPos);
 452         }
 453     }
 454     return false;
 455 }
 456
 457 bool KItemListView::isAboveText(int index, const QPointF &pos) const
 458 {
 459     const KItemListWidget *widget = m_visibleItems.value(index);
 460     if (widget) {
 461         const QRectF &textRect = widget->textRect();
 462         if (!textRect.isEmpty()) {
 463             const QPointF mappedPos = widget->mapFromItem(this, pos);
 464             return textRect.contains(mappedPos);
 465         }
 466     }
 467     return false;
 468 }
 469
 470 int KItemListView::firstVisibleIndex() const
 471 {
 472     return m_layouter->firstVisibleIndex();
 473 }
 474
 475 int KItemListView::lastVisibleIndex() const
 476 {
 477     return m_layouter->lastVisibleIndex();
 478 }
 479
 480 void KItemListView::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint) const
 481 {
 482     widgetCreator()->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, this);
 483 }
 484
 485 void KItemListView::setSupportsItemExpanding(bool supportsExpanding)
 486 {
 487     if (m_supportsItemExpanding != supportsExpanding) {
 488         m_supportsItemExpanding = supportsExpanding;
 489         updateSiblingsInformation();
 490         onSupportsItemExpandingChanged(supportsExpanding);
 491     }
 492 }
 493
 494 bool KItemListView::supportsItemExpanding() const
 495 {
 496     return m_supportsItemExpanding;
 497 }
 498
 499 void KItemListView::setHighlightEntireRow(bool highlightEntireRow)
 500 {
 501     if (m_highlightEntireRow != highlightEntireRow) {
 502         m_highlightEntireRow = highlightEntireRow;
 503         onHighlightEntireRowChanged(highlightEntireRow);
 504     }
 505 }
 506
 507 bool KItemListView::highlightEntireRow() const
 508 {
 509     return m_highlightEntireRow;
 510 }
 511
 512 void KItemListView::setAlternateBackgrounds(bool alternate)
 513 {
 514     if (m_alternateBackgrounds != alternate) {
 515         m_alternateBackgrounds = alternate;
 516         updateAlternateBackgrounds();
 517     }
 518 }
 519
 520 bool KItemListView::alternateBackgrounds() const
 521 {
 522     return m_alternateBackgrounds;
 523 }
 524
 525 QRectF KItemListView::itemRect(int index) const
 526 {
 527     return m_layouter->itemRect(index);
 528 }
 529
 530 QRectF KItemListView::itemContextRect(int index) const
 531 {
 532     QRectF contextRect;
 533
 534     const KItemListWidget *widget = m_visibleItems.value(index);
 535     if (widget) {
 536         contextRect = widget->iconRect() | widget->textRect();
 537         contextRect.translate(itemRect(index).topLeft());
 538     }
 539
 540     return contextRect;
 541 }
 542
 543 bool KItemListView::isElided(int index) const
 544 {
 545     return m_sizeHintResolver->isElided(index);
 546 }
 547
 548 void KItemListView::scrollToItem(int index, ViewItemPosition viewItemPosition)
 549 {
 550     QRectF viewGeometry = geometry();
 551     if (m_headerWidget->isVisible()) {
 552         const qreal headerHeight = m_headerWidget->size().height();
 553         viewGeometry.adjust(0, headerHeight, 0, 0);
 554     }
 555     QRectF currentRect = itemRect(index);
 556
 557     if (layoutDirection() == Qt::RightToLeft && scrollOrientation() == Qt::Horizontal) {
 558         currentRect.moveLeft(m_layouter->size().width() - currentRect.right());
 559     }
 560
 561     // Fix for Bug 311099 - View the underscore when using Ctrl + PageDown
 562     currentRect.adjust(-m_styleOption.horizontalMargin, -m_styleOption.verticalMargin, m_styleOption.horizontalMargin, m_styleOption.verticalMargin);
 563
 564     qreal offset = 0;
 565     switch (scrollOrientation()) {
 566     case Qt::Vertical:
 567         if (currentRect.top() < viewGeometry.top() || currentRect.bottom() > viewGeometry.bottom()) {
 568             switch (viewItemPosition) {
 569             case Beginning:
 570                 offset = currentRect.top() - viewGeometry.top();
 571                 break;
 572             case Middle:
 573                 offset = 0.5 * (currentRect.top() + currentRect.bottom() - (viewGeometry.top() + viewGeometry.bottom()));
 574                 break;
 575             case End:
 576                 offset = currentRect.bottom() - viewGeometry.bottom();
 577                 break;
 578             case Nearest:
 579                 if (currentRect.top() < viewGeometry.top()) {
 580                     offset = currentRect.top() - viewGeometry.top();
 581                 }
 582                 if (currentRect.bottom() > viewGeometry.bottom() + offset) {
 583                     offset += currentRect.bottom() - viewGeometry.bottom() - offset;
 584                 }
 585                 break;
 586             default:
 587                 Q_UNREACHABLE();
 588             }
 589         }
 590         break;
 591     case Qt::Horizontal:
 592         if (currentRect.left() < viewGeometry.left() || currentRect.right() > viewGeometry.right()) {
 593             switch (viewItemPosition) {
 594             case Beginning:
 595                 if (layoutDirection() == Qt::RightToLeft) {
 596                     offset = currentRect.right() - viewGeometry.right();
 597                 } else {
 598                     offset = currentRect.left() - viewGeometry.left();
 599                 }
 600                 break;
 601             case Middle:
 602                 offset = 0.5 * (currentRect.left() + currentRect.right() - (viewGeometry.left() + viewGeometry.right()));
 603                 break;
 604             case End:
 605                 if (layoutDirection() == Qt::RightToLeft) {
 606                     offset = currentRect.left() - viewGeometry.left();
 607                 } else {
 608                     offset = currentRect.right() - viewGeometry.right();
 609                 }
 610                 break;
 611             case Nearest:
 612                 if (layoutDirection() == Qt::RightToLeft) {
 613                     if (currentRect.left() < viewGeometry.left()) {
 614                         offset = currentRect.left() - viewGeometry.left();
 615                     }
 616                     if (currentRect.right() > viewGeometry.right() + offset) {
 617                         offset += currentRect.right() - viewGeometry.right() - offset;
 618                     }
 619                 } else {
 620                     if (currentRect.right() > viewGeometry.right()) {
 621                         offset = currentRect.right() - viewGeometry.right();
 622                     }
 623                     if (currentRect.left() < viewGeometry.left() + offset) {
 624                         offset += currentRect.left() - viewGeometry.left() - offset;
 625                     }
 626                 }
 627                 break;
 628             default:
 629                 Q_UNREACHABLE();
 630             }
 631         }
 632         break;
 633     default:
 634         Q_UNREACHABLE();
 635     }
 636
 637     if (!qFuzzyIsNull(offset)) {
 638         Q_EMIT scrollTo(scrollOffset() + offset);
 639         return;
 640     }
 641
 642     Q_EMIT scrollingStopped();
 643 }
 644
 645 void KItemListView::beginTransaction()
 646 {
 647     ++m_activeTransactions;
 648     if (m_activeTransactions == 1) {
 649         onTransactionBegin();
 650     }
 651 }
 652
 653 void KItemListView::endTransaction()
 654 {
 655     --m_activeTransactions;
 656     if (m_activeTransactions < 0) {
 657         m_activeTransactions = 0;
 658         qCWarning(DolphinDebug) << "Mismatch between beginTransaction()/endTransaction()";
 659     }
 660
 661     if (m_activeTransactions == 0) {
 662         onTransactionEnd();
 663         doLayout(m_endTransactionAnimationHint);
 664         m_endTransactionAnimationHint = Animation;
 665     }
 666 }
 667
 668 bool KItemListView::isTransactionActive() const
 669 {
 670     return m_activeTransactions > 0;
 671 }
 672
 673 void KItemListView::setHeaderVisible(bool visible)
 674 {
 675     if (visible && !m_headerWidget->isVisible()) {
 676         QStyleOptionHeader option;
 677         const QSize headerSize = style()->sizeFromContents(QStyle::CT_HeaderSection, &option, QSize());
 678
 679         m_headerWidget->setPos(0, 0);
 680         m_headerWidget->resize(size().width(), headerSize.height());
 681         m_headerWidget->setModel(m_model);
 682         m_headerWidget->setColumns(m_visibleRoles);
 683         m_headerWidget->setZValue(1);
 684
 685         connect(m_headerWidget, &KItemListHeaderWidget::columnWidthChanged, this, &KItemListView::slotHeaderColumnWidthChanged);
 686         connect(m_headerWidget, &KItemListHeaderWidget::sidePaddingChanged, this, &KItemListView::slotSidePaddingChanged);
 687         connect(m_headerWidget, &KItemListHeaderWidget::columnMoved, this, &KItemListView::slotHeaderColumnMoved);
 688         connect(m_headerWidget, &KItemListHeaderWidget::sortOrderChanged, this, &KItemListView::sortOrderChanged);
 689         connect(m_headerWidget, &KItemListHeaderWidget::sortRoleChanged, this, &KItemListView::sortRoleChanged);
 690         connect(m_headerWidget, &KItemListHeaderWidget::columnHovered, this, &KItemListView::columnHovered);
 691         connect(m_headerWidget, &KItemListHeaderWidget::columnUnHovered, this, &KItemListView::columnUnHovered);
 692
 693         m_layouter->setHeaderHeight(headerSize.height());
 694         m_headerWidget->setVisible(true);
 695     } else if (!visible && m_headerWidget->isVisible()) {
 696         disconnect(m_headerWidget, &KItemListHeaderWidget::columnWidthChanged, this, &KItemListView::slotHeaderColumnWidthChanged);
 697         disconnect(m_headerWidget, &KItemListHeaderWidget::sidePaddingChanged, this, &KItemListView::slotSidePaddingChanged);
 698         disconnect(m_headerWidget, &KItemListHeaderWidget::columnMoved, this, &KItemListView::slotHeaderColumnMoved);
 699         disconnect(m_headerWidget, &KItemListHeaderWidget::sortOrderChanged, this, &KItemListView::sortOrderChanged);
 700         disconnect(m_headerWidget, &KItemListHeaderWidget::sortRoleChanged, this, &KItemListView::sortRoleChanged);
 701         disconnect(m_headerWidget, &KItemListHeaderWidget::columnHovered, this, &KItemListView::columnHovered);
 702         disconnect(m_headerWidget, &KItemListHeaderWidget::columnUnHovered, this, &KItemListView::columnUnHovered);
 703
 704         m_layouter->setHeaderHeight(0);
 705         m_headerWidget->setVisible(false);
 706     }
 707 }
 708
 709 bool KItemListView::isHeaderVisible() const
 710 {
 711     return m_headerWidget->isVisible();
 712 }
 713
 714 KItemListHeader *KItemListView::header() const
 715 {
 716     return m_header;
 717 }
 718
 719 QPixmap KItemListView::createDragPixmap(const KItemSet &indexes) const
 720 {
 721     QPixmap pixmap;
 722
 723     if (indexes.count() == 1) {
 724         KItemListWidget *item = m_visibleItems.value(indexes.first());
 725         QGraphicsView *graphicsView = scene()->views()[0];
 726         if (item && graphicsView) {
 727             pixmap = item->createDragPixmap(nullptr, graphicsView);
 728         }
 729     } else {
 730         // TODO: Not implemented yet. Probably extend the interface
 731         // from KItemListWidget::createDragPixmap() to return a pixmap
 732         // that can be used for multiple indexes.
 733     }
 734
 735     return pixmap;
 736 }
 737
 738 void KItemListView::editRole(int index, const QByteArray &role)
 739 {
 740     KStandardItemListWidget *widget = qobject_cast<KStandardItemListWidget *>(m_visibleItems.value(index));
 741     if (!widget || m_editingRole) {
 742         return;
 743     }
 744
 745     m_editingRole = true;
 746     widget->setEditedRole(role);
 747
 748     connect(widget, &KItemListWidget::roleEditingCanceled, this, &KItemListView::slotRoleEditingCanceled);
 749     connect(widget, &KItemListWidget::roleEditingFinished, this, &KItemListView::slotRoleEditingFinished);
 750
 751     connect(this, &KItemListView::scrollOffsetChanged, widget, &KStandardItemListWidget::finishRoleEditing);
 752 }
 753
 754 void KItemListView::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
 755 {
 756     QGraphicsWidget::paint(painter, option, widget);
 757
 758     for (auto animation : std::as_const(m_rubberBandAnimations)) {
 759         QRectF rubberBandRect = animation->property(RubberPropertyName).toRectF();
 760
 761         const QPointF topLeft = rubberBandRect.topLeft();
 762         if (scrollOrientation() == Qt::Vertical) {
 763             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 764         } else {
 765             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 766         }
 767
 768         QStyleOptionRubberBand opt;
 769         initStyleOption(&opt);
 770         opt.shape = QRubberBand::Rectangle;
 771         opt.opaque = false;
 772         opt.rect = rubberBandRect.toRect();
 773
 774         painter->save();
 775
 776         painter->setOpacity(animation->currentValue().toReal());
 777         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 778
 779         painter->restore();
 780     }
 781
 782     if (m_rubberBand->isActive()) {
 783         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(), m_rubberBand->endPosition()).normalized();
 784
 785         const QPointF topLeft = rubberBandRect.topLeft();
 786         if (scrollOrientation() == Qt::Vertical) {
 787             rubberBandRect.moveTo(topLeft.x(), topLeft.y() - scrollOffset());
 788         } else {
 789             rubberBandRect.moveTo(topLeft.x() - scrollOffset(), topLeft.y());
 790         }
 791
 792         QStyleOptionRubberBand opt;
 793         initStyleOption(&opt);
 794         opt.shape = QRubberBand::Rectangle;
 795         opt.opaque = false;
 796         opt.rect = rubberBandRect.toRect();
 797         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 798     }
 799
 800     if (m_tapAndHoldIndicator->isActive()) {
 801         const QPointF indicatorSize = m_tapAndHoldIndicator->endPosition();
 802         const QRectF rubberBandRect =
 803             QRectF(m_tapAndHoldIndicator->startPosition() - indicatorSize, (m_tapAndHoldIndicator->startPosition()) + indicatorSize).normalized();
 804         QStyleOptionRubberBand opt;
 805         initStyleOption(&opt);
 806         opt.shape = QRubberBand::Rectangle;
 807         opt.opaque = false;
 808         opt.rect = rubberBandRect.toRect();
 809         style()->drawControl(QStyle::CE_RubberBand, &opt, painter);
 810     }
 811
 812     if (!m_dropIndicator.isEmpty()) {
 813         const QRectF r = m_dropIndicator.toRect();
 814
 815         QColor color = palette().brush(QPalette::Normal, QPalette::Text).color();
 816         painter->setPen(color);
 817
 818         // TODO: The following implementation works only for a vertical scroll-orientation
 819         // and assumes a height of the m_draggingInsertIndicator of 1.
 820         Q_ASSERT(r.height() == 1);
 821         painter->drawLine(r.left() + 1, r.top(), r.right() - 1, r.top());
 822
 823         color.setAlpha(128);
 824         painter->setPen(color);
 825         painter->drawRect(r.left(), r.top() - 1, r.width() - 1, 2);
 826     }
 827 }
 828
 829 QVariant KItemListView::itemChange(GraphicsItemChange change, const QVariant &value)
 830 {
 831     if (change == QGraphicsItem::ItemSceneHasChanged && scene()) {
 832         if (!scene()->views().isEmpty()) {
 833             m_styleOption.palette = scene()->views().at(0)->palette();
 834         }
 835     }
 836     return QGraphicsItem::itemChange(change, value);
 837 }
 838
 839 void KItemListView::setItemSize(const QSizeF &size)
 840 {
 841     const QSizeF previousSize = m_itemSize;
 842     if (size == previousSize) {
 843         return;
 844     }
 845
 846     // Skip animations when the number of rows or columns
 847     // are changed in the grid layout. Although the animation
 848     // engine can handle this usecase, it looks obtrusive.
 849     const bool animate = !changesItemGridLayout(m_layouter->size(), size, m_layouter->itemMargin());
 850
 851     const bool alternateBackgroundsChanged = m_alternateBackgrounds && ((m_itemSize.isEmpty() && !size.isEmpty()) || (!m_itemSize.isEmpty() && size.isEmpty()));
 852
 853     m_itemSize = size;
 854
 855     if (alternateBackgroundsChanged) {
 856         // For an empty item size alternate backgrounds are drawn if more than
 857         // one role is shown. Assure that the backgrounds for visible items are
 858         // updated when changing the size in this context.
 859         updateAlternateBackgrounds();
 860     }
 861
 862     if (size.isEmpty()) {
 863         if (m_headerWidget->automaticColumnResizing()) {
 864             updatePreferredColumnWidths();
 865         } else {
 866             // Only apply the changed height and respect the header widths
 867             // set by the user
 868             const qreal currentWidth = m_layouter->itemSize().width();
 869             const QSizeF newSize(currentWidth, size.height());
 870             m_layouter->setItemSize(newSize);
 871         }
 872     } else {
 873         m_layouter->setItemSize(size);
 874     }
 875
 876     m_sizeHintResolver->clearCache();
 877     doLayout(animate ? Animation : NoAnimation);
 878     onItemSizeChanged(size, previousSize);
 879 }
 880
 881 void KItemListView::setStyleOption(const KItemListStyleOption &option)
 882 {
 883     if (m_styleOption == option) {
 884         return;
 885     }
 886
 887     const KItemListStyleOption previousOption = m_styleOption;
 888     m_styleOption = option;
 889
 890     bool animate = true;
 891     const QSizeF margin(option.horizontalMargin, option.verticalMargin);
 892     if (margin != m_layouter->itemMargin()) {
 893         // Skip animations when the number of rows or columns
 894         // are changed in the grid layout. Although the animation
 895         // engine can handle this usecase, it looks obtrusive.
 896         animate = !changesItemGridLayout(m_layouter->size(), m_layouter->itemSize(), margin);
 897         m_layouter->setItemMargin(margin);
 898     }
 899
 900     if (m_grouped) {
 901         updateGroupHeaderHeight();
 902     }
 903
 904     if (animate && (previousOption.maxTextLines != option.maxTextLines || previousOption.maxTextWidth != option.maxTextWidth)) {
 905         // Animating a change of the maximum text size just results in expensive
 906         // temporary eliding and clipping operations and does not look good visually.
 907         animate = false;
 908     }
 909
 910     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
 911     while (it.hasNext()) {
 912         it.next();
 913         it.value()->setStyleOption(option);
 914     }
 915
 916     m_sizeHintResolver->clearCache();
 917     m_layouter->markAsDirty();
 918     doLayout(animate ? Animation : NoAnimation);
 919
 920     if (m_itemSize.isEmpty()) {
 921         updatePreferredColumnWidths();
 922     }
 923
 924     onStyleOptionChanged(option, previousOption);
 925 }
 926
 927 void KItemListView::setScrollOrientation(Qt::Orientation orientation)
 928 {
 929     const Qt::Orientation previousOrientation = m_layouter->scrollOrientation();
 930     if (orientation == previousOrientation) {
 931         return;
 932     }
 933
 934     m_layouter->setScrollOrientation(orientation);
 935     m_animation->setScrollOrientation(orientation);
 936     m_sizeHintResolver->clearCache();
 937
 938     if (m_grouped) {
 939         QMutableHashIterator<KItemListWidget *, KItemListGroupHeader *> it(m_visibleGroups);
 940         while (it.hasNext()) {
 941             it.next();
 942             it.value()->setScrollOrientation(orientation);
 943         }
 944         updateGroupHeaderHeight();
 945     }
 946
 947     doLayout(NoAnimation);
 948
 949     onScrollOrientationChanged(orientation, previousOrientation);
 950     Q_EMIT scrollOrientationChanged(orientation, previousOrientation);
 951 }
 952
 953 Qt::Orientation KItemListView::scrollOrientation() const
 954 {
 955     return m_layouter->scrollOrientation();
 956 }
 957
 958 KItemListWidgetCreatorBase *KItemListView::defaultWidgetCreator() const
 959 {
 960     return nullptr;
 961 }
 962
 963 KItemListGroupHeaderCreatorBase *KItemListView::defaultGroupHeaderCreator() const
 964 {
 965     return nullptr;
 966 }
 967
 968 void KItemListView::initializeItemListWidget(KItemListWidget *item)
 969 {
 970     Q_UNUSED(item)
 971 }
 972
 973 bool KItemListView::itemSizeHintUpdateRequired(const QSet<QByteArray> &changedRoles) const
 974 {
 975     Q_UNUSED(changedRoles)
 976     return true;
 977 }
 978
 979 void KItemListView::onControllerChanged(KItemListController *current, KItemListController *previous)
 980 {
 981     Q_UNUSED(current)
 982     Q_UNUSED(previous)
 983 }
 984
 985 void KItemListView::onModelChanged(KItemModelBase *current, KItemModelBase *previous)
 986 {
 987     Q_UNUSED(current)
 988     Q_UNUSED(previous)
 989 }
 990
 991 void KItemListView::onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous)
 992 {
 993     Q_UNUSED(current)
 994     Q_UNUSED(previous)
 995 }
 996
 997 void KItemListView::onItemSizeChanged(const QSizeF &current, const QSizeF &previous)
 998 {
 999     Q_UNUSED(current)
1000     Q_UNUSED(previous)
1001 }
1002
1003 void KItemListView::onScrollOffsetChanged(qreal current, qreal previous)
1004 {
1005     Q_UNUSED(current)
1006     Q_UNUSED(previous)
1007 }
1008
1009 void KItemListView::onVisibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous)
1010 {
1011     Q_UNUSED(current)
1012     Q_UNUSED(previous)
1013 }
1014
1015 void KItemListView::onStyleOptionChanged(const KItemListStyleOption &current, const KItemListStyleOption &previous)
1016 {
1017     Q_UNUSED(current)
1018     Q_UNUSED(previous)
1019 }
1020
1021 void KItemListView::onHighlightEntireRowChanged(bool highlightEntireRow)
1022 {
1023     Q_UNUSED(highlightEntireRow)
1024 }
1025
1026 void KItemListView::onSupportsItemExpandingChanged(bool supportsExpanding)
1027 {
1028     Q_UNUSED(supportsExpanding)
1029 }
1030
1031 void KItemListView::onTransactionBegin()
1032 {
1033 }
1034
1035 void KItemListView::onTransactionEnd()
1036 {
1037 }
1038
1039 bool KItemListView::event(QEvent *event)
1040 {
1041     switch (event->type()) {
1042     case QEvent::PaletteChange:
1043         updatePalette();
1044         break;
1045
1046     case QEvent::FontChange:
1047         updateFont();
1048         break;
1049
1050     case QEvent::FocusIn:
1051         focusInEvent(static_cast<QFocusEvent *>(event));
1052         event->accept();
1053         return true;
1054         break;
1055
1056     case QEvent::FocusOut:
1057         focusOutEvent(static_cast<QFocusEvent *>(event));
1058         event->accept();
1059         return true;
1060         break;
1061
1062     default:
1063         // Forward all other events to the controller and handle them there
1064         if (!m_editingRole && m_controller && m_controller->processEvent(event, transform())) {
1065             event->accept();
1066             return true;
1067         }
1068     }
1069
1070     return QGraphicsWidget::event(event);
1071 }
1072
1073 void KItemListView::mousePressEvent(QGraphicsSceneMouseEvent *event)
1074 {
1075     m_mousePos = transform().map(event->pos());
1076     event->accept();
1077 }
1078
1079 void KItemListView::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
1080 {
1081     QGraphicsWidget::mouseMoveEvent(event);
1082
1083     m_mousePos = transform().map(event->pos());
1084     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
1085         m_autoScrollTimer->start(InitialAutoScrollDelay);
1086     }
1087 }
1088
1089 void KItemListView::dragEnterEvent(QGraphicsSceneDragDropEvent *event)
1090 {
1091     event->setAccepted(true);
1092     setAutoScroll(true);
1093 }
1094
1095 void KItemListView::dragMoveEvent(QGraphicsSceneDragDropEvent *event)
1096 {
1097     QGraphicsWidget::dragMoveEvent(event);
1098
1099     m_mousePos = transform().map(event->pos());
1100     if (m_autoScrollTimer && !m_autoScrollTimer->isActive()) {
1101         m_autoScrollTimer->start(InitialAutoScrollDelay);
1102     }
1103 }
1104
1105 void KItemListView::dragLeaveEvent(QGraphicsSceneDragDropEvent *event)
1106 {
1107     QGraphicsWidget::dragLeaveEvent(event);
1108     setAutoScroll(false);
1109 }
1110
1111 void KItemListView::dropEvent(QGraphicsSceneDragDropEvent *event)
1112 {
1113     QGraphicsWidget::dropEvent(event);
1114     setAutoScroll(false);
1115 }
1116
1117 QList<KItemListWidget *> KItemListView::visibleItemListWidgets() const
1118 {
1119     return m_visibleItems.values();
1120 }
1121
1122 void KItemListView::updateFont()
1123 {
1124     if (scene() && !scene()->views().isEmpty()) {
1125         KItemListStyleOption option = styleOption();
1126         option.font = scene()->views().first()->font();
1127         option.fontMetrics = QFontMetrics(option.font);
1128
1129         setStyleOption(option);
1130     }
1131 }
1132
1133 void KItemListView::updatePalette()
1134 {
1135     KItemListStyleOption option = styleOption();
1136     option.palette = palette();
1137     setStyleOption(option);
1138 }
1139
1140 void KItemListView::slotItemsInserted(const KItemRangeList &itemRanges)
1141 {
1142     if (m_itemSize.isEmpty()) {
1143         updatePreferredColumnWidths(itemRanges);
1144     }
1145
1146     const bool hasMultipleRanges = (itemRanges.count() > 1);
1147     if (hasMultipleRanges) {
1148         beginTransaction();
1149     }
1150
1151     m_layouter->markAsDirty();
1152
1153     m_sizeHintResolver->itemsInserted(itemRanges);
1154
1155     int previouslyInsertedCount = 0;
1156     for (const KItemRange &range : itemRanges) {
1157         // range.index is related to the model before anything has been inserted.
1158         // As in each loop the current item-range gets inserted the index must
1159         // be increased by the already previously inserted items.
1160         const int index = range.index + previouslyInsertedCount;
1161         const int count = range.count;
1162         if (index < 0 || count <= 0) {
1163             qCWarning(DolphinDebug) << "Invalid item range (index:" << index << ", count:" << count << ")";
1164             continue;
1165         }
1166         previouslyInsertedCount += count;
1167
1168         // Determine which visible items must be moved
1169         QList<int> itemsToMove;
1170         QHashIterator<int, KItemListWidget *> it(m_visibleItems);
1171         while (it.hasNext()) {
1172             it.next();
1173             const int visibleItemIndex = it.key();
1174             if (visibleItemIndex >= index) {
1175                 itemsToMove.append(visibleItemIndex);
1176             }
1177         }
1178
1179         // Update the indexes of all KItemListWidget instances that are located
1180         // after the inserted items. It is important to adjust the indexes in the order
1181         // from the highest index to the lowest index to prevent overlaps when setting the new index.
1182         std::sort(itemsToMove.begin(), itemsToMove.end());
1183         for (int i = itemsToMove.count() - 1; i >= 0; --i) {
1184             KItemListWidget *widget = m_visibleItems.value(itemsToMove[i]);
1185             Q_ASSERT(widget);
1186             const int newIndex = widget->index() + count;
1187             if (hasMultipleRanges) {
1188                 setWidgetIndex(widget, newIndex);
1189             } else {
1190                 // Try to animate the moving of the item
1191                 moveWidgetToIndex(widget, newIndex);
1192             }
1193         }
1194
1195         if (m_model->count() == count && m_activeTransactions == 0) {
1196             // Check whether a scrollbar is required to show the inserted items. In this case
1197             // the size of the layouter will be decreased before calling doLayout(): This prevents
1198             // an unnecessary temporary animation due to the geometry change of the inserted scrollbar.
1199             const bool verticalScrollOrientation = (scrollOrientation() == Qt::Vertical);
1200             const bool decreaseLayouterSize = (verticalScrollOrientation && maximumScrollOffset() > size().height())
1201                 || (!verticalScrollOrientation && maximumScrollOffset() > size().width());
1202             if (decreaseLayouterSize) {
1203                 const int scrollBarExtent = style()->pixelMetric(QStyle::PM_ScrollBarExtent);
1204
1205                 int scrollbarSpacing = 0;
1206                 if (style()->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents)) {
1207                     scrollbarSpacing = style()->pixelMetric(QStyle::PM_ScrollView_ScrollBarSpacing);
1208                 }
1209
1210                 QSizeF layouterSize = m_layouter->size();
1211                 if (verticalScrollOrientation) {
1212                     layouterSize.rwidth() -= scrollBarExtent + scrollbarSpacing;
1213                 } else {
1214                     layouterSize.rheight() -= scrollBarExtent + scrollbarSpacing;
1215                 }
1216                 m_layouter->setSize(layouterSize);
1217             }
1218         }
1219
1220         if (!hasMultipleRanges) {
1221             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, count);
1222             updateSiblingsInformation();
1223         }
1224     }
1225
1226     if (m_controller) {
1227         m_controller->selectionManager()->itemsInserted(itemRanges);
1228     }
1229
1230     if (hasMultipleRanges) {
1231         m_endTransactionAnimationHint = NoAnimation;
1232         endTransaction();
1233
1234         updateSiblingsInformation();
1235     }
1236
1237     if (m_grouped && (hasMultipleRanges || itemRanges.first().count < m_model->count())) {
1238         // In case if items of the same group have been inserted before an item that
1239         // currently represents the first item of the group, the group header of
1240         // this item must be removed.
1241         updateVisibleGroupHeaders();
1242     }
1243
1244     if (useAlternateBackgrounds()) {
1245         updateAlternateBackgrounds();
1246     }
1247 }
1248
1249 void KItemListView::slotItemsRemoved(const KItemRangeList &itemRanges)
1250 {
1251     if (m_itemSize.isEmpty()) {
1252         // Don't pass the item-range: The preferred column-widths of
1253         // all items must be adjusted when removing items.
1254         updatePreferredColumnWidths();
1255     }
1256
1257     const bool hasMultipleRanges = (itemRanges.count() > 1);
1258     if (hasMultipleRanges) {
1259         beginTransaction();
1260     }
1261
1262     m_layouter->markAsDirty();
1263
1264     m_sizeHintResolver->itemsRemoved(itemRanges);
1265
1266     for (int i = itemRanges.count() - 1; i >= 0; --i) {
1267         const KItemRange &range = itemRanges[i];
1268         const int index = range.index;
1269         const int count = range.count;
1270         if (index < 0 || count <= 0) {
1271             qCWarning(DolphinDebug) << "Invalid item range (index:" << index << ", count:" << count << ")";
1272             continue;
1273         }
1274
1275         const int firstRemovedIndex = index;
1276         const int lastRemovedIndex = index + count - 1;
1277
1278         // Remember which items have to be moved because they are behind the removed range.
1279         QVector<int> itemsToMove;
1280
1281         // Remove all KItemListWidget instances that got deleted
1282         // Iterate over a const copy because the container is mutated within the loop
1283         // directly and in `recycleWidget()` (https://bugs.kde.org/show_bug.cgi?id=428374)
1284         const auto visibleItems = m_visibleItems;
1285         for (KItemListWidget *widget : visibleItems) {
1286             const int i = widget->index();
1287             if (i < firstRemovedIndex) {
1288                 continue;
1289             } else if (i > lastRemovedIndex) {
1290                 itemsToMove.append(i);
1291                 continue;
1292             }
1293
1294             m_animation->stop(widget);
1295             // Stopping the animation might lead to recycling the widget if
1296             // it is invisible (see slotAnimationFinished()).
1297             // Check again whether it is still visible:
1298             if (!m_visibleItems.contains(i)) {
1299                 continue;
1300             }
1301
1302             if (m_model->count() == 0 || hasMultipleRanges || !animateChangedItemCount(count)) {
1303                 // Remove the widget without animation
1304                 recycleWidget(widget);
1305             } else {
1306                 // Animate the removing of the items. Special case: When removing an item there
1307                 // is no valid model index available anymore. For the
1308                 // remove-animation the item gets removed from m_visibleItems but the widget
1309                 // will stay alive until the animation has been finished and will
1310                 // be recycled (deleted) in KItemListView::slotAnimationFinished().
1311                 m_visibleItems.remove(i);
1312                 widget->setIndex(-1);
1313                 m_animation->start(widget, KItemListViewAnimation::DeleteAnimation);
1314             }
1315         }
1316
1317         // Update the indexes of all KItemListWidget instances that are located
1318         // after the deleted items. It is important to update them in ascending
1319         // order to prevent overlaps when setting the new index.
1320         std::sort(itemsToMove.begin(), itemsToMove.end());
1321         for (int i : std::as_const(itemsToMove)) {
1322             KItemListWidget *widget = m_visibleItems.value(i);
1323             Q_ASSERT(widget);
1324             const int newIndex = i - count;
1325             if (hasMultipleRanges) {
1326                 setWidgetIndex(widget, newIndex);
1327             } else {
1328                 // Try to animate the moving of the item
1329                 moveWidgetToIndex(widget, newIndex);
1330             }
1331         }
1332
1333         if (!hasMultipleRanges) {
1334             // The decrease-layout-size optimization in KItemListView::slotItemsInserted()
1335             // assumes an updated geometry. If items are removed during an active transaction,
1336             // the transaction will be temporary deactivated so that doLayout() triggers a
1337             // geometry update if necessary.
1338             const int activeTransactions = m_activeTransactions;
1339             m_activeTransactions = 0;
1340             doLayout(animateChangedItemCount(count) ? Animation : NoAnimation, index, -count);
1341             m_activeTransactions = activeTransactions;
1342             updateSiblingsInformation();
1343         }
1344     }
1345
1346     if (m_controller) {
1347         m_controller->selectionManager()->itemsRemoved(itemRanges);
1348     }
1349
1350     if (hasMultipleRanges) {
1351         m_endTransactionAnimationHint = NoAnimation;
1352         endTransaction();
1353         updateSiblingsInformation();
1354     }
1355
1356     if (m_grouped && (hasMultipleRanges || m_model->count() > 0)) {
1357         // In case if the first item of a group has been removed, the group header
1358         // must be applied to the next visible item.
1359         updateVisibleGroupHeaders();
1360     }
1361
1362     if (useAlternateBackgrounds()) {
1363         updateAlternateBackgrounds();
1364     }
1365 }
1366
1367 void KItemListView::slotItemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes)
1368 {
1369     m_sizeHintResolver->itemsMoved(itemRange, movedToIndexes);
1370     m_layouter->markAsDirty();
1371
1372     if (m_controller) {
1373         m_controller->selectionManager()->itemsMoved(itemRange, movedToIndexes);
1374     }
1375
1376     const int firstVisibleMovedIndex = qMax(firstVisibleIndex(), itemRange.index);
1377     const int lastVisibleMovedIndex = qMin(lastVisibleIndex(), itemRange.index + itemRange.count - 1);
1378
1379     for (int index = firstVisibleMovedIndex; index <= lastVisibleMovedIndex; ++index) {
1380         KItemListWidget *widget = m_visibleItems.value(index);
1381         if (widget) {
1382             updateWidgetProperties(widget, index);
1383             initializeItemListWidget(widget);
1384         }
1385     }
1386
1387     doLayout(NoAnimation);
1388     updateSiblingsInformation();
1389 }
1390
1391 void KItemListView::slotItemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles)
1392 {
1393     const bool updateSizeHints = itemSizeHintUpdateRequired(roles);
1394     if (updateSizeHints && m_itemSize.isEmpty()) {
1395         updatePreferredColumnWidths(itemRanges);
1396     }
1397
1398     for (const KItemRange &itemRange : itemRanges) {
1399         const int index = itemRange.index;
1400         const int count = itemRange.count;
1401
1402         if (updateSizeHints) {
1403             m_sizeHintResolver->itemsChanged(index, count, roles);
1404             m_layouter->markAsDirty();
1405         }
1406
1407         // Apply the changed roles to the visible item-widgets
1408         const int lastIndex = index + count - 1;
1409         for (int i = index; i <= lastIndex; ++i) {
1410             KItemListWidget *widget = m_visibleItems.value(i);
1411             if (widget) {
1412                 widget->setData(m_model->data(i), roles);
1413             }
1414         }
1415
1416         if (m_grouped && roles.contains(m_model->sortRole())) {
1417             // The sort-role has been changed which might result
1418             // in modified group headers
1419             updateVisibleGroupHeaders();
1420             doLayout(NoAnimation);
1421         }
1422     }
1423     doLayout(NoAnimation);
1424 }
1425
1426 void KItemListView::slotGroupsChanged()
1427 {
1428     updateVisibleGroupHeaders();
1429     doLayout(NoAnimation);
1430     updateSiblingsInformation();
1431 }
1432
1433 void KItemListView::slotGroupedSortingChanged(bool current)
1434 {
1435     m_grouped = current;
1436     m_layouter->markAsDirty();
1437
1438     if (m_grouped) {
1439         updateGroupHeaderHeight();
1440     } else {
1441         // Clear all visible headers. Note that the QHashIterator takes a copy of
1442         // m_visibleGroups. Therefore, it remains valid even if items are removed
1443         // from m_visibleGroups in recycleGroupHeaderForWidget().
1444         QHashIterator<KItemListWidget *, KItemListGroupHeader *> it(m_visibleGroups);
1445         while (it.hasNext()) {
1446             it.next();
1447             recycleGroupHeaderForWidget(it.key());
1448         }
1449         Q_ASSERT(m_visibleGroups.isEmpty());
1450     }
1451
1452     if (useAlternateBackgrounds()) {
1453         // Changing the group mode requires to update the alternate backgrounds
1454         // as with the enabled group mode the altering is done on base of the first
1455         // group item.
1456         updateAlternateBackgrounds();
1457     }
1458     updateSiblingsInformation();
1459     doLayout(NoAnimation);
1460 }
1461
1462 void KItemListView::slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
1463 {
1464     Q_UNUSED(current)
1465     Q_UNUSED(previous)
1466     if (m_grouped) {
1467         updateVisibleGroupHeaders();
1468         doLayout(NoAnimation);
1469     }
1470 }
1471
1472 void KItemListView::slotSortRoleChanged(const QByteArray &current, const QByteArray &previous)
1473 {
1474     Q_UNUSED(current)
1475     Q_UNUSED(previous)
1476     if (m_grouped) {
1477         updateVisibleGroupHeaders();
1478         doLayout(NoAnimation);
1479     }
1480 }
1481
1482 void KItemListView::slotCurrentChanged(int current, int previous)
1483 {
1484     // In SingleSelection mode (e.g., in the Places Panel), the current item is
1485     // always the selected item. It is not necessary to highlight the current item then.
1486     if (m_controller->selectionBehavior() != KItemListController::SingleSelection) {
1487         KItemListWidget *previousWidget = m_visibleItems.value(previous, nullptr);
1488         if (previousWidget) {
1489             previousWidget->setCurrent(false);
1490         }
1491
1492         KItemListWidget *currentWidget = m_visibleItems.value(current, nullptr);
1493         if (currentWidget) {
1494             currentWidget->setCurrent(true);
1495         }
1496     }
1497 #ifndef QT_NO_ACCESSIBILITY
1498     if (current != previous && QAccessible::isActive()) {
1499         static_cast<KItemListViewAccessible *>(QAccessible::queryAccessibleInterface(this))->announceCurrentItem();
1500     }
1501 #endif
1502 }
1503
1504 void KItemListView::slotSelectionChanged(const KItemSet &current, const KItemSet &previous)
1505 {
1506     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
1507     while (it.hasNext()) {
1508         it.next();
1509         const int index = it.key();
1510         KItemListWidget *widget = it.value();
1511         const bool isSelected(current.contains(index));
1512         widget->setSelected(isSelected);
1513
1514 #ifndef QT_NO_ACCESSIBILITY
1515         if (!QAccessible::isActive()) {
1516             continue;
1517         }
1518         // Let the screen reader announce "selected" or "not selected" for the active item.
1519         const bool wasSelected(previous.contains(index));
1520         if (isSelected != wasSelected) {
1521             QAccessibleEvent accessibleSelectionChangedEvent(this, QAccessible::SelectionAdd);
1522             accessibleSelectionChangedEvent.setChild(index);
1523             QAccessible::updateAccessibility(&accessibleSelectionChangedEvent);
1524         }
1525     }
1526 #else
1527     }
1528     Q_UNUSED(previous)
1529 #endif
1530 }
1531
1532 void KItemListView::slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type)
1533 {
1534     KItemListWidget *itemListWidget = qobject_cast<KItemListWidget *>(widget);
1535     Q_ASSERT(itemListWidget);
1536
1537     if (type == KItemListViewAnimation::DeleteAnimation) {
1538         // As we recycle the widget in this case it is important to assure that no
1539         // other animation has been started. This is a convention in KItemListView and
1540         // not a requirement defined by KItemListViewAnimation.
1541         Q_ASSERT(!m_animation->isStarted(itemListWidget));
1542
1543         // All KItemListWidgets that are animated by the DeleteAnimation are not maintained
1544         // by m_visibleWidgets and must be deleted manually after the animation has
1545         // been finished.
1546         recycleGroupHeaderForWidget(itemListWidget);
1547         widgetCreator()->recycle(itemListWidget);
1548     } else {
1549         const int index = itemListWidget->index();
1550         const bool invisible = (index < m_layouter->firstVisibleIndex()) || (index > m_layouter->lastVisibleIndex());
1551         if (invisible && !m_animation->isStarted(itemListWidget)) {
1552             recycleWidget(itemListWidget);
1553         }
1554     }
1555 }
1556
1557 void KItemListView::slotRubberBandPosChanged()
1558 {
1559     update();
1560 }
1561
1562 void KItemListView::slotRubberBandActivationChanged(bool active)
1563 {
1564     if (active) {
1565         connect(m_rubberBand, &KItemListRubberBand::startPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1566         connect(m_rubberBand, &KItemListRubberBand::endPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1567         m_skipAutoScrollForRubberBand = true;
1568     } else {
1569         QRectF rubberBandRect = QRectF(m_rubberBand->startPosition(), m_rubberBand->endPosition()).normalized();
1570
1571         auto animation = new QVariantAnimation(this);
1572         animation->setStartValue(1.0);
1573         animation->setEndValue(0.0);
1574         animation->setDuration(RubberFadeSpeed);
1575         animation->setProperty(RubberPropertyName, rubberBandRect);
1576
1577         QEasingCurve curve;
1578         curve.setType(QEasingCurve::BezierSpline);
1579         curve.addCubicBezierSegment(QPointF(0.4, 0.0), QPointF(1.0, 1.0), QPointF(1.0, 1.0));
1580         animation->setEasingCurve(curve);
1581
1582         connect(animation, &QVariantAnimation::valueChanged, this, [=, this](const QVariant &) {
1583             update();
1584         });
1585         connect(animation, &QVariantAnimation::finished, this, [=, this]() {
1586             m_rubberBandAnimations.removeAll(animation);
1587             delete animation;
1588         });
1589         animation->start();
1590         m_rubberBandAnimations << animation;
1591
1592         disconnect(m_rubberBand, &KItemListRubberBand::startPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1593         disconnect(m_rubberBand, &KItemListRubberBand::endPositionChanged, this, &KItemListView::slotRubberBandPosChanged);
1594         m_skipAutoScrollForRubberBand = false;
1595     }
1596
1597     update();
1598 }
1599
1600 void KItemListView::slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth)
1601 {
1602     Q_UNUSED(role)
1603     Q_UNUSED(currentWidth)
1604     Q_UNUSED(previousWidth)
1605
1606     m_headerWidget->setAutomaticColumnResizing(false);
1607     applyColumnWidthsFromHeader();
1608     doLayout(NoAnimation);
1609 }
1610
1611 void KItemListView::slotSidePaddingChanged(qreal width)
1612 {
1613     Q_UNUSED(width)
1614     if (m_headerWidget->automaticColumnResizing()) {
1615         applyAutomaticColumnWidths();
1616     }
1617     applyColumnWidthsFromHeader();
1618     doLayout(NoAnimation);
1619 }
1620
1621 void KItemListView::slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex)
1622 {
1623     Q_ASSERT(m_visibleRoles[previousIndex] == role);
1624
1625     const QList<QByteArray> previous = m_visibleRoles;
1626
1627     QList<QByteArray> current = m_visibleRoles;
1628     current.removeAt(previousIndex);
1629     current.insert(currentIndex, role);
1630
1631     setVisibleRoles(current);
1632
1633     Q_EMIT visibleRolesChanged(current, previous);
1634 }
1635
1636 void KItemListView::triggerAutoScrolling()
1637 {
1638     if (!m_autoScrollTimer) {
1639         return;
1640     }
1641
1642     int pos = 0;
1643     int visibleSize = 0;
1644     if (scrollOrientation() == Qt::Vertical) {
1645         pos = m_mousePos.y();
1646         visibleSize = size().height();
1647     } else {
1648         pos = m_mousePos.x();
1649         visibleSize = size().width();
1650     }
1651
1652     if (m_autoScrollTimer->interval() == InitialAutoScrollDelay) {
1653         m_autoScrollIncrement = 0;
1654     }
1655
1656     m_autoScrollIncrement = calculateAutoScrollingIncrement(pos, visibleSize, m_autoScrollIncrement);
1657     if (m_autoScrollIncrement == 0) {
1658         // The mouse position is not above an autoscroll margin (the autoscroll timer
1659         // will be restarted in mouseMoveEvent())
1660         m_autoScrollTimer->stop();
1661         return;
1662     }
1663
1664     if (m_rubberBand->isActive() && m_skipAutoScrollForRubberBand) {
1665         // If a rubberband selection is ongoing the autoscrolling may only get triggered
1666         // if the direction of the rubberband is similar to the autoscroll direction. This
1667         // prevents that starting to create a rubberband within the autoscroll margins starts
1668         // an autoscrolling.
1669
1670         const qreal minDiff = 4; // Ignore any autoscrolling if the rubberband is very small
1671         const qreal diff = (scrollOrientation() == Qt::Vertical) ? m_rubberBand->endPosition().y() - m_rubberBand->startPosition().y()
1672                                                                  : m_rubberBand->endPosition().x() - m_rubberBand->startPosition().x();
1673         if (qAbs(diff) < minDiff || (m_autoScrollIncrement < 0 && diff > 0) || (m_autoScrollIncrement > 0 && diff < 0)) {
1674             // The rubberband direction is different from the scroll direction (e.g. the rubberband has
1675             // been moved up although the autoscroll direction might be down)
1676             m_autoScrollTimer->stop();
1677             return;
1678         }
1679     }
1680
1681     // As soon as the autoscrolling has been triggered at least once despite having an active rubberband,
1682     // the autoscrolling may not get skipped anymore until a new rubberband is created
1683     m_skipAutoScrollForRubberBand = false;
1684
1685     const qreal maxVisibleOffset = qMax(qreal(0), maximumScrollOffset() - visibleSize);
1686     const qreal newScrollOffset = qMin(scrollOffset() + m_autoScrollIncrement, maxVisibleOffset);
1687     setScrollOffset(newScrollOffset);
1688
1689     // Trigger the autoscroll timer which will periodically call
1690     // triggerAutoScrolling()
1691     m_autoScrollTimer->start(RepeatingAutoScrollDelay);
1692 }
1693
1694 void KItemListView::slotGeometryOfGroupHeaderParentChanged()
1695 {
1696     KItemListWidget *widget = qobject_cast<KItemListWidget *>(sender());
1697     Q_ASSERT(widget);
1698     KItemListGroupHeader *groupHeader = m_visibleGroups.value(widget);
1699     Q_ASSERT(groupHeader);
1700     updateGroupHeaderLayout(widget);
1701 }
1702
1703 void KItemListView::slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value)
1704 {
1705     disconnectRoleEditingSignals(index);
1706
1707     m_editingRole = false;
1708     Q_EMIT roleEditingCanceled(index, role, value);
1709 }
1710
1711 void KItemListView::slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value)
1712 {
1713     disconnectRoleEditingSignals(index);
1714
1715     m_editingRole = false;
1716     Q_EMIT roleEditingFinished(index, role, value);
1717 }
1718
1719 void KItemListView::setController(KItemListController *controller)
1720 {
1721     if (m_controller != controller) {
1722         KItemListController *previous = m_controller;
1723         if (previous) {
1724             KItemListSelectionManager *selectionManager = previous->selectionManager();
1725             disconnect(selectionManager, &KItemListSelectionManager::currentChanged, this, &KItemListView::slotCurrentChanged);
1726             disconnect(selectionManager, &KItemListSelectionManager::selectionChanged, this, &KItemListView::slotSelectionChanged);
1727         }
1728
1729         m_controller = controller;
1730
1731         if (controller) {
1732             KItemListSelectionManager *selectionManager = controller->selectionManager();
1733             connect(selectionManager, &KItemListSelectionManager::currentChanged, this, &KItemListView::slotCurrentChanged);
1734             connect(selectionManager, &KItemListSelectionManager::selectionChanged, this, &KItemListView::slotSelectionChanged);
1735         }
1736
1737         onControllerChanged(controller, previous);
1738     }
1739 }
1740
1741 void KItemListView::setModel(KItemModelBase *model)
1742 {
1743     if (m_model == model) {
1744         return;
1745     }
1746
1747     KItemModelBase *previous = m_model;
1748
1749     if (m_model) {
1750         disconnect(m_model, &KItemModelBase::itemsChanged, this, &KItemListView::slotItemsChanged);
1751         disconnect(m_model, &KItemModelBase::itemsInserted, this, &KItemListView::slotItemsInserted);
1752         disconnect(m_model, &KItemModelBase::itemsRemoved, this, &KItemListView::slotItemsRemoved);
1753         disconnect(m_model, &KItemModelBase::itemsMoved, this, &KItemListView::slotItemsMoved);
1754         disconnect(m_model, &KItemModelBase::groupsChanged, this, &KItemListView::slotGroupsChanged);
1755         disconnect(m_model, &KItemModelBase::groupedSortingChanged, this, &KItemListView::slotGroupedSortingChanged);
1756         disconnect(m_model, &KItemModelBase::sortOrderChanged, this, &KItemListView::slotSortOrderChanged);
1757         disconnect(m_model, &KItemModelBase::sortRoleChanged, this, &KItemListView::slotSortRoleChanged);
1758
1759         m_sizeHintResolver->itemsRemoved(KItemRangeList() << KItemRange(0, m_model->count()));
1760     }
1761
1762     m_model = model;
1763     m_layouter->setModel(model);
1764     m_grouped = model->groupedSorting();
1765
1766     if (m_model) {
1767         connect(m_model, &KItemModelBase::itemsChanged, this, &KItemListView::slotItemsChanged);
1768         connect(m_model, &KItemModelBase::itemsInserted, this, &KItemListView::slotItemsInserted);
1769         connect(m_model, &KItemModelBase::itemsRemoved, this, &KItemListView::slotItemsRemoved);
1770         connect(m_model, &KItemModelBase::itemsMoved, this, &KItemListView::slotItemsMoved);
1771         connect(m_model, &KItemModelBase::groupsChanged, this, &KItemListView::slotGroupsChanged);
1772         connect(m_model, &KItemModelBase::groupedSortingChanged, this, &KItemListView::slotGroupedSortingChanged);
1773         connect(m_model, &KItemModelBase::sortOrderChanged, this, &KItemListView::slotSortOrderChanged);
1774         connect(m_model, &KItemModelBase::sortRoleChanged, this, &KItemListView::slotSortRoleChanged);
1775
1776         const int itemCount = m_model->count();
1777         if (itemCount > 0) {
1778             slotItemsInserted(KItemRangeList() << KItemRange(0, itemCount));
1779         }
1780     }
1781
1782     onModelChanged(model, previous);
1783 }
1784
1785 KItemListRubberBand *KItemListView::rubberBand() const
1786 {
1787     return m_rubberBand;
1788 }
1789
1790 void KItemListView::doLayout(LayoutAnimationHint hint, int changedIndex, int changedCount)
1791 {
1792     if (m_activeTransactions > 0) {
1793         if (hint == NoAnimation) {
1794             // As soon as at least one property change should be done without animation,
1795             // the whole transaction will be marked as not animated.
1796             m_endTransactionAnimationHint = NoAnimation;
1797         }
1798         return;
1799     }
1800
1801     if (!m_model || m_model->count() < 0) {
1802         return;
1803     }
1804
1805     int firstVisibleIndex = m_layouter->firstVisibleIndex();
1806     if (firstVisibleIndex < 0) {
1807         emitOffsetChanges();
1808         return;
1809     }
1810
1811     // Do a sanity check of the scroll-offset property: When properties of the itemlist-view have been changed
1812     // it might be possible that the maximum offset got changed too. Assure that the full visible range
1813     // is still shown if the maximum offset got decreased.
1814     const qreal visibleOffsetRange = (scrollOrientation() == Qt::Horizontal) ? size().width() : size().height();
1815     const qreal maxOffsetToShowFullRange = maximumScrollOffset() - visibleOffsetRange;
1816     if (scrollOffset() > maxOffsetToShowFullRange) {
1817         m_layouter->setScrollOffset(qMax(qreal(0), maxOffsetToShowFullRange));
1818         firstVisibleIndex = m_layouter->firstVisibleIndex();
1819     }
1820
1821     const int lastVisibleIndex = m_layouter->lastVisibleIndex();
1822
1823     int firstSibblingIndex = -1;
1824     int lastSibblingIndex = -1;
1825     const bool supportsExpanding = supportsItemExpanding();
1826
1827     QList<int> reusableItems = recycleInvisibleItems(firstVisibleIndex, lastVisibleIndex, hint);
1828
1829     // Assure that for each visible item a KItemListWidget is available. KItemListWidget
1830     // instances from invisible items are reused. If no reusable items are
1831     // found then new KItemListWidget instances get created.
1832     const bool animate = (hint == Animation);
1833     for (int i = firstVisibleIndex; i <= lastVisibleIndex; ++i) {
1834         bool applyNewPos = true;
1835
1836         const QRectF itemBounds = m_layouter->itemRect(i);
1837         const QPointF newPos = itemBounds.topLeft();
1838         KItemListWidget *widget = m_visibleItems.value(i);
1839         if (!widget) {
1840             if (!reusableItems.isEmpty()) {
1841                 // Reuse a KItemListWidget instance from an invisible item
1842                 const int oldIndex = reusableItems.takeLast();
1843                 widget = m_visibleItems.value(oldIndex);
1844                 setWidgetIndex(widget, i);
1845                 updateWidgetProperties(widget, i);
1846                 initializeItemListWidget(widget);
1847             } else {
1848                 // No reusable KItemListWidget instance is available, create a new one
1849                 widget = createWidget(i);
1850             }
1851             widget->resize(itemBounds.size());
1852
1853             if (animate && changedCount < 0) {
1854                 // Items have been deleted.
1855                 if (i >= changedIndex) {
1856                     // The item is located behind the removed range. Move the
1857                     // created item to the imaginary old position outside the
1858                     // view. It will get animated to the new position later.
1859                     const int previousIndex = i - changedCount;
1860                     const QRectF itemRect = m_layouter->itemRect(previousIndex);
1861                     if (itemRect.isEmpty()) {
1862                         const QPointF invisibleOldPos = (scrollOrientation() == Qt::Vertical) ? QPointF(0, size().height()) : QPointF(size().width(), 0);
1863                         widget->setPos(invisibleOldPos);
1864                     } else {
1865                         widget->setPos(itemRect.topLeft());
1866                     }
1867                     applyNewPos = false;
1868                 }
1869             }
1870
1871             if (supportsExpanding && changedCount == 0) {
1872                 if (firstSibblingIndex < 0) {
1873                     firstSibblingIndex = i;
1874                 }
1875                 lastSibblingIndex = i;
1876             }
1877         }
1878
1879         if (animate) {
1880             if (m_animation->isStarted(widget, KItemListViewAnimation::MovingAnimation)) {
1881                 m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
1882                 applyNewPos = false;
1883             }
1884
1885             const bool itemsRemoved = (changedCount < 0);
1886             const bool itemsInserted = (changedCount > 0);
1887             if (itemsRemoved && (i >= changedIndex)) {
1888                 // The item is located after the removed items. Animate the moving of the position.
1889                 applyNewPos = !moveWidget(widget, newPos);
1890             } else if (itemsInserted && i >= changedIndex) {
1891                 // The item is located after the first inserted item
1892                 if (i <= changedIndex + changedCount - 1) {
1893                     // The item is an inserted item. Animate the appearing of the item.
1894                     // For performance reasons no animation is done when changedCount is equal
1895                     // to all available items.
1896                     if (changedCount < m_model->count()) {
1897                         m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
1898                     }
1899                 } else if (!m_animation->isStarted(widget, KItemListViewAnimation::CreateAnimation)) {
1900                     // The item was already there before, so animate the moving of the position.
1901                     // No moving animation is done if the item is animated by a create animation: This
1902                     // prevents a "move animation mess" when inserting several ranges in parallel.
1903                     applyNewPos = !moveWidget(widget, newPos);
1904                 }
1905             }
1906         } else {
1907             m_animation->stop(widget);
1908         }
1909
1910         if (applyNewPos) {
1911             widget->setPos(newPos);
1912         }
1913
1914         Q_ASSERT(widget->index() == i);
1915         widget->setVisible(true);
1916
1917         bool animateIconResizing = animate;
1918
1919         if (widget->size() != itemBounds.size()) {
1920             // Resize the widget for the item to the changed size.
1921             if (animate) {
1922                 // If a dynamic item size is used then no animation is done in the direction
1923                 // of the dynamic size.
1924                 if (m_itemSize.width() <= 0) {
1925                     // The width is dynamic, apply the new width without animation.
1926                     widget->resize(itemBounds.width(), widget->size().height());
1927                 } else if (m_itemSize.height() <= 0) {
1928                     // The height is dynamic, apply the new height without animation.
1929                     widget->resize(widget->size().width(), itemBounds.height());
1930                 }
1931                 m_animation->start(widget, KItemListViewAnimation::ResizeAnimation, itemBounds.size());
1932             } else {
1933                 widget->resize(itemBounds.size());
1934             }
1935         } else {
1936             animateIconResizing = false;
1937         }
1938
1939         const int newIconSize = widget->styleOption().iconSize;
1940         if (widget->iconSize() != newIconSize) {
1941             if (animateIconResizing) {
1942                 m_animation->start(widget, KItemListViewAnimation::IconResizeAnimation, newIconSize);
1943             } else {
1944                 widget->setIconSize(newIconSize);
1945             }
1946         }
1947
1948         // Updating the cell-information must be done as last step: The decision whether the
1949         // moving-animation should be started at all is based on the previous cell-information.
1950         const Cell cell(m_layouter->itemColumn(i), m_layouter->itemRow(i));
1951         m_visibleCells.insert(i, cell);
1952     }
1953
1954     // Delete invisible KItemListWidget instances that have not been reused
1955     for (int index : std::as_const(reusableItems)) {
1956         recycleWidget(m_visibleItems.value(index));
1957     }
1958
1959     if (supportsExpanding && firstSibblingIndex >= 0) {
1960         Q_ASSERT(lastSibblingIndex >= 0);
1961         updateSiblingsInformation(firstSibblingIndex, lastSibblingIndex);
1962     }
1963
1964     if (m_grouped) {
1965         // Update the layout of all visible group headers
1966         QHashIterator<KItemListWidget *, KItemListGroupHeader *> it(m_visibleGroups);
1967         while (it.hasNext()) {
1968             it.next();
1969             updateGroupHeaderLayout(it.key());
1970         }
1971     }
1972
1973     emitOffsetChanges();
1974 }
1975
1976 QList<int> KItemListView::recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint)
1977 {
1978     // Determine all items that are completely invisible and might be
1979     // reused for items that just got (at least partly) visible. If the
1980     // animation hint is set to 'Animation' items that do e.g. an animated
1981     // moving of their position are not marked as invisible: This assures
1982     // that a scrolling inside the view can be done without breaking an animation.
1983
1984     QList<int> items;
1985
1986     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
1987     while (it.hasNext()) {
1988         it.next();
1989
1990         KItemListWidget *widget = it.value();
1991         const int index = widget->index();
1992         const bool invisible = (index < firstVisibleIndex) || (index > lastVisibleIndex);
1993
1994         if (invisible) {
1995             if (m_animation->isStarted(widget)) {
1996                 if (hint == NoAnimation) {
1997                     // Stopping the animation will call KItemListView::slotAnimationFinished()
1998                     // and the widget will be recycled if necessary there.
1999                     m_animation->stop(widget);
2000                 }
2001             } else {
2002                 widget->setVisible(false);
2003                 items.append(index);
2004
2005                 if (m_grouped) {
2006                     recycleGroupHeaderForWidget(widget);
2007                 }
2008             }
2009         }
2010     }
2011
2012     return items;
2013 }
2014
2015 bool KItemListView::moveWidget(KItemListWidget *widget, const QPointF &newPos)
2016 {
2017     if (widget->pos() == newPos) {
2018         return false;
2019     }
2020
2021     bool startMovingAnim = false;
2022
2023     if (m_itemSize.isEmpty()) {
2024         // The items are not aligned in a grid but either as columns or rows.
2025         startMovingAnim = true;
2026     } else {
2027         // When having a grid the moving-animation should only be started, if it is done within
2028         // one row in the vertical scroll-orientation or one column in the horizontal scroll-orientation.
2029         // Otherwise instead of a moving-animation a create-animation on the new position will be used
2030         // instead. This is done to prevent overlapping (and confusing) moving-animations.
2031         const int index = widget->index();
2032         const Cell cell = m_visibleCells.value(index);
2033         if (cell.column >= 0 && cell.row >= 0) {
2034             if (scrollOrientation() == Qt::Vertical) {
2035                 startMovingAnim = (cell.row == m_layouter->itemRow(index));
2036             } else {
2037                 startMovingAnim = (cell.column == m_layouter->itemColumn(index));
2038             }
2039         }
2040     }
2041
2042     if (startMovingAnim) {
2043         m_animation->start(widget, KItemListViewAnimation::MovingAnimation, newPos);
2044         return true;
2045     }
2046
2047     m_animation->stop(widget);
2048     m_animation->start(widget, KItemListViewAnimation::CreateAnimation);
2049     return false;
2050 }
2051
2052 void KItemListView::emitOffsetChanges()
2053 {
2054     const qreal newScrollOffset = m_layouter->scrollOffset();
2055     if (m_oldScrollOffset != newScrollOffset) {
2056         Q_EMIT scrollOffsetChanged(newScrollOffset, m_oldScrollOffset);
2057         m_oldScrollOffset = newScrollOffset;
2058     }
2059
2060     const qreal newMaximumScrollOffset = m_layouter->maximumScrollOffset();
2061     if (m_oldMaximumScrollOffset != newMaximumScrollOffset) {
2062         Q_EMIT maximumScrollOffsetChanged(newMaximumScrollOffset, m_oldMaximumScrollOffset);
2063         m_oldMaximumScrollOffset = newMaximumScrollOffset;
2064     }
2065
2066     const qreal newItemOffset = m_layouter->itemOffset();
2067     if (m_oldItemOffset != newItemOffset) {
2068         Q_EMIT itemOffsetChanged(newItemOffset, m_oldItemOffset);
2069         m_oldItemOffset = newItemOffset;
2070     }
2071
2072     const qreal newMaximumItemOffset = m_layouter->maximumItemOffset();
2073     if (m_oldMaximumItemOffset != newMaximumItemOffset) {
2074         Q_EMIT maximumItemOffsetChanged(newMaximumItemOffset, m_oldMaximumItemOffset);
2075         m_oldMaximumItemOffset = newMaximumItemOffset;
2076     }
2077 }
2078
2079 KItemListWidget *KItemListView::createWidget(int index)
2080 {
2081     KItemListWidget *widget = widgetCreator()->create(this);
2082     widget->setFlag(QGraphicsItem::ItemStacksBehindParent);
2083
2084     m_visibleItems.insert(index, widget);
2085     m_visibleCells.insert(index, Cell());
2086     updateWidgetProperties(widget, index);
2087     initializeItemListWidget(widget);
2088     return widget;
2089 }
2090
2091 void KItemListView::recycleWidget(KItemListWidget *widget)
2092 {
2093     if (m_grouped) {
2094         recycleGroupHeaderForWidget(widget);
2095     }
2096
2097     const int index = widget->index();
2098     m_visibleItems.remove(index);
2099     m_visibleCells.remove(index);
2100
2101     widgetCreator()->recycle(widget);
2102 }
2103
2104 void KItemListView::setWidgetIndex(KItemListWidget *widget, int index)
2105 {
2106     const int oldIndex = widget->index();
2107     m_visibleItems.remove(oldIndex);
2108     m_visibleCells.remove(oldIndex);
2109
2110     m_visibleItems.insert(index, widget);
2111     m_visibleCells.insert(index, Cell());
2112
2113     widget->setIndex(index);
2114 }
2115
2116 void KItemListView::moveWidgetToIndex(KItemListWidget *widget, int index)
2117 {
2118     const int oldIndex = widget->index();
2119     const Cell oldCell = m_visibleCells.value(oldIndex);
2120
2121     setWidgetIndex(widget, index);
2122
2123     const Cell newCell(m_layouter->itemColumn(index), m_layouter->itemRow(index));
2124     const bool vertical = (scrollOrientation() == Qt::Vertical);
2125     const bool updateCell = (vertical && oldCell.row == newCell.row) || (!vertical && oldCell.column == newCell.column);
2126     if (updateCell) {
2127         m_visibleCells.insert(index, newCell);
2128     }
2129 }
2130
2131 void KItemListView::setLayouterSize(const QSizeF &size, SizeType sizeType)
2132 {
2133     switch (sizeType) {
2134     case LayouterSize:
2135         m_layouter->setSize(size);
2136         break;
2137     case ItemSize:
2138         m_layouter->setItemSize(size);
2139         break;
2140     default:
2141         break;
2142     }
2143 }
2144
2145 void KItemListView::updateWidgetProperties(KItemListWidget *widget, int index)
2146 {
2147     widget->setVisibleRoles(m_visibleRoles);
2148     updateWidgetColumnWidths(widget);
2149     widget->setStyleOption(m_styleOption);
2150
2151     const KItemListSelectionManager *selectionManager = m_controller->selectionManager();
2152
2153     // In SingleSelection mode (e.g., in the Places Panel), the current item is
2154     // always the selected item. It is not necessary to highlight the current item then.
2155     if (m_controller->selectionBehavior() != KItemListController::SingleSelection) {
2156         widget->setCurrent(index == selectionManager->currentItem());
2157     }
2158     widget->setSelected(selectionManager->isSelected(index));
2159     widget->setHovered(false);
2160     widget->setEnabledSelectionToggle(enabledSelectionToggles());
2161     widget->setIndex(index);
2162     widget->setData(m_model->data(index));
2163     widget->setSiblingsInformation(QBitArray());
2164     updateAlternateBackgroundForWidget(widget);
2165
2166     if (m_grouped) {
2167         updateGroupHeaderForWidget(widget);
2168     }
2169 }
2170
2171 void KItemListView::updateGroupHeaderForWidget(KItemListWidget *widget)
2172 {
2173     Q_ASSERT(m_grouped);
2174
2175     const int index = widget->index();
2176     if (!m_layouter->isFirstGroupItem(index)) {
2177         // The widget does not represent the first item of a group
2178         // and hence requires no header
2179         recycleGroupHeaderForWidget(widget);
2180         return;
2181     }
2182
2183     const QList<QPair<int, QVariant>> groups = model()->groups();
2184     if (groups.isEmpty() || !groupHeaderCreator()) {
2185         return;
2186     }
2187
2188     KItemListGroupHeader *groupHeader = m_visibleGroups.value(widget);
2189     if (!groupHeader) {
2190         groupHeader = groupHeaderCreator()->create(this);
2191         groupHeader->setParentItem(widget);
2192         m_visibleGroups.insert(widget, groupHeader);
2193         connect(widget, &KItemListWidget::geometryChanged, this, &KItemListView::slotGeometryOfGroupHeaderParentChanged);
2194     }
2195     Q_ASSERT(groupHeader->parentItem() == widget);
2196
2197     const int groupIndex = groupIndexForItem(index);
2198     Q_ASSERT(groupIndex >= 0);
2199     groupHeader->setData(groups.at(groupIndex).second);
2200     groupHeader->setRole(model()->sortRole());
2201     groupHeader->setStyleOption(m_styleOption);
2202     groupHeader->setScrollOrientation(scrollOrientation());
2203     groupHeader->setItemIndex(index);
2204
2205     groupHeader->show();
2206 }
2207
2208 void KItemListView::updateGroupHeaderLayout(KItemListWidget *widget)
2209 {
2210     KItemListGroupHeader *groupHeader = m_visibleGroups.value(widget);
2211     Q_ASSERT(groupHeader);
2212
2213     const int index = widget->index();
2214     const QRectF groupHeaderRect = m_layouter->groupHeaderRect(index);
2215     const QRectF itemRect = m_layouter->itemRect(index);
2216
2217     // The group-header is a child of the itemlist widget. Translate the
2218     // group header position to the relative position.
2219     if (scrollOrientation() == Qt::Vertical) {
2220         // In the vertical scroll orientation the group header should always span
2221         // the whole width no matter which temporary position the parent widget
2222         // has. In this case the x-position and width will be adjusted manually.
2223         const qreal x = -widget->x() - itemOffset();
2224         const qreal width = maximumItemOffset();
2225         groupHeader->setPos(x, -groupHeaderRect.height());
2226         groupHeader->resize(width, groupHeaderRect.size().height());
2227     } else {
2228         groupHeader->setPos(groupHeaderRect.x() - itemRect.x(), -widget->y());
2229         groupHeader->resize(groupHeaderRect.size());
2230     }
2231 }
2232
2233 void KItemListView::recycleGroupHeaderForWidget(KItemListWidget *widget)
2234 {
2235     KItemListGroupHeader *header = m_visibleGroups.value(widget);
2236     if (header) {
2237         header->setParentItem(nullptr);
2238         groupHeaderCreator()->recycle(header);
2239         m_visibleGroups.remove(widget);
2240         disconnect(widget, &KItemListWidget::geometryChanged, this, &KItemListView::slotGeometryOfGroupHeaderParentChanged);
2241     }
2242 }
2243
2244 void KItemListView::updateVisibleGroupHeaders()
2245 {
2246     Q_ASSERT(m_grouped);
2247     m_layouter->markAsDirty();
2248
2249     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2250     while (it.hasNext()) {
2251         it.next();
2252         updateGroupHeaderForWidget(it.value());
2253     }
2254 }
2255
2256 int KItemListView::groupIndexForItem(int index) const
2257 {
2258     Q_ASSERT(m_grouped);
2259
2260     const QList<QPair<int, QVariant>> groups = model()->groups();
2261     if (groups.isEmpty()) {
2262         return -1;
2263     }
2264
2265     int min = 0;
2266     int max = groups.count() - 1;
2267     int mid = 0;
2268     do {
2269         mid = (min + max) / 2;
2270         if (index > groups[mid].first) {
2271             min = mid + 1;
2272         } else {
2273             max = mid - 1;
2274         }
2275     } while (groups[mid].first != index && min <= max);
2276
2277     if (min > max) {
2278         while (groups[mid].first > index && mid > 0) {
2279             --mid;
2280         }
2281     }
2282
2283     return mid;
2284 }
2285
2286 void KItemListView::updateAlternateBackgrounds()
2287 {
2288     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2289     while (it.hasNext()) {
2290         it.next();
2291         updateAlternateBackgroundForWidget(it.value());
2292     }
2293 }
2294
2295 void KItemListView::updateAlternateBackgroundForWidget(KItemListWidget *widget)
2296 {
2297     bool enabled = useAlternateBackgrounds();
2298     if (enabled) {
2299         const int index = widget->index();
2300         enabled = (index & 0x1) > 0;
2301         if (m_grouped) {
2302             const int groupIndex = groupIndexForItem(index);
2303             if (groupIndex >= 0) {
2304                 const QList<QPair<int, QVariant>> groups = model()->groups();
2305                 const int indexOfFirstGroupItem = groups[groupIndex].first;
2306                 const int relativeIndex = index - indexOfFirstGroupItem;
2307                 enabled = (relativeIndex & 0x1) > 0;
2308             }
2309         }
2310     }
2311     widget->setAlternateBackground(enabled);
2312 }
2313
2314 bool KItemListView::useAlternateBackgrounds() const
2315 {
2316     return m_alternateBackgrounds && m_itemSize.isEmpty();
2317 }
2318
2319 QHash<QByteArray, qreal> KItemListView::preferredColumnWidths(const KItemRangeList &itemRanges) const
2320 {
2321     QElapsedTimer timer;
2322     timer.start();
2323
2324     QHash<QByteArray, qreal> widths;
2325
2326     // Calculate the minimum width for each column that is required
2327     // to show the headline unclipped.
2328     const QFontMetricsF fontMetrics(m_headerWidget->font());
2329     const int gripMargin = m_headerWidget->style()->pixelMetric(QStyle::PM_HeaderGripMargin);
2330     const int headerMargin = m_headerWidget->style()->pixelMetric(QStyle::PM_HeaderMargin);
2331     for (const QByteArray &visibleRole : std::as_const(m_visibleRoles)) {
2332         const QString headerText = m_model->roleDescription(visibleRole);
2333         const qreal headerWidth = fontMetrics.horizontalAdvance(headerText) + gripMargin + headerMargin * 2;
2334         widths.insert(visibleRole, headerWidth);
2335     }
2336
2337     // Calculate the preferred column widths for each item and ignore values
2338     // smaller than the width for showing the headline unclipped.
2339     const KItemListWidgetCreatorBase *creator = widgetCreator();
2340     int calculatedItemCount = 0;
2341     bool maxTimeExceeded = false;
2342     for (const KItemRange &itemRange : itemRanges) {
2343         const int startIndex = itemRange.index;
2344         const int endIndex = startIndex + itemRange.count - 1;
2345
2346         for (int i = startIndex; i <= endIndex; ++i) {
2347             for (const QByteArray &visibleRole : std::as_const(m_visibleRoles)) {
2348                 qreal maxWidth = widths.value(visibleRole, 0);
2349                 const qreal width = creator->preferredRoleColumnWidth(visibleRole, i, this);
2350                 maxWidth = qMax(width, maxWidth);
2351                 widths.insert(visibleRole, maxWidth);
2352             }
2353
2354             if (calculatedItemCount > 100 && timer.elapsed() > 200) {
2355                 // When having several thousands of items calculating the sizes can get
2356                 // very expensive. We accept a possibly too small role-size in favour
2357                 // of having no blocking user interface.
2358                 maxTimeExceeded = true;
2359                 break;
2360             }
2361             ++calculatedItemCount;
2362         }
2363         if (maxTimeExceeded) {
2364             break;
2365         }
2366     }
2367
2368     return widths;
2369 }
2370
2371 void KItemListView::applyColumnWidthsFromHeader()
2372 {
2373     // Apply the new size to the layouter
2374     const qreal requiredWidth = columnWidthsSum() + 2 * m_headerWidget->sidePadding();
2375     const QSizeF dynamicItemSize(qMax(size().width(), requiredWidth), m_itemSize.height());
2376     m_layouter->setItemSize(dynamicItemSize);
2377
2378     // Update the role sizes for all visible widgets
2379     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2380     while (it.hasNext()) {
2381         it.next();
2382         updateWidgetColumnWidths(it.value());
2383     }
2384 }
2385
2386 void KItemListView::updateWidgetColumnWidths(KItemListWidget *widget)
2387 {
2388     for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2389         widget->setColumnWidth(role, m_headerWidget->columnWidth(role));
2390     }
2391     widget->setSidePadding(m_headerWidget->sidePadding());
2392 }
2393
2394 void KItemListView::updatePreferredColumnWidths(const KItemRangeList &itemRanges)
2395 {
2396     Q_ASSERT(m_itemSize.isEmpty());
2397     const int itemCount = m_model->count();
2398     int rangesItemCount = 0;
2399     for (const KItemRange &range : itemRanges) {
2400         rangesItemCount += range.count;
2401     }
2402
2403     if (itemCount == rangesItemCount) {
2404         const QHash<QByteArray, qreal> preferredWidths = preferredColumnWidths(itemRanges);
2405         for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2406             m_headerWidget->setPreferredColumnWidth(role, preferredWidths.value(role));
2407         }
2408     } else {
2409         // Only a sub range of the roles need to be determined.
2410         // The chances are good that the widths of the sub ranges
2411         // already fit into the available widths and hence no
2412         // expensive update might be required.
2413         bool changed = false;
2414
2415         const QHash<QByteArray, qreal> updatedWidths = preferredColumnWidths(itemRanges);
2416         QHashIterator<QByteArray, qreal> it(updatedWidths);
2417         while (it.hasNext()) {
2418             it.next();
2419             const QByteArray &role = it.key();
2420             const qreal updatedWidth = it.value();
2421             const qreal currentWidth = m_headerWidget->preferredColumnWidth(role);
2422             if (updatedWidth > currentWidth) {
2423                 m_headerWidget->setPreferredColumnWidth(role, updatedWidth);
2424                 changed = true;
2425             }
2426         }
2427
2428         if (!changed) {
2429             // All the updated sizes are smaller than the current sizes and no change
2430             // of the stretched roles-widths is required
2431             return;
2432         }
2433     }
2434
2435     if (m_headerWidget->automaticColumnResizing()) {
2436         applyAutomaticColumnWidths();
2437     }
2438 }
2439
2440 void KItemListView::updatePreferredColumnWidths()
2441 {
2442     if (m_model) {
2443         updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()));
2444     }
2445 }
2446
2447 void KItemListView::applyAutomaticColumnWidths()
2448 {
2449     Q_ASSERT(m_itemSize.isEmpty());
2450     Q_ASSERT(m_headerWidget->automaticColumnResizing());
2451     if (m_visibleRoles.isEmpty()) {
2452         return;
2453     }
2454
2455     // Calculate the maximum size of an item by considering the
2456     // visible role sizes and apply them to the layouter. If the
2457     // size does not use the available view-size the size of the
2458     // first role will get stretched.
2459
2460     for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2461         const qreal preferredWidth = m_headerWidget->preferredColumnWidth(role);
2462         m_headerWidget->setColumnWidth(role, preferredWidth);
2463     }
2464
2465     const QByteArray firstRole = m_visibleRoles.first();
2466     qreal firstColumnWidth = m_headerWidget->columnWidth(firstRole);
2467     QSizeF dynamicItemSize = m_itemSize;
2468
2469     qreal requiredWidth = columnWidthsSum() + 2 * m_headerWidget->sidePadding(); // Adding the padding a second time so we have the same padding
2470     // symmetrically on both sides of the view. This improves UX, looks better and increases the chances of users figuring out that the padding
2471     // area can be used for deselecting and dropping files.
2472     const qreal availableWidth = size().width();
2473     if (requiredWidth < availableWidth) {
2474         // Stretch the first column to use the whole remaining width
2475         firstColumnWidth += availableWidth - requiredWidth;
2476         m_headerWidget->setColumnWidth(firstRole, firstColumnWidth);
2477     } else if (requiredWidth > availableWidth && m_visibleRoles.count() > 1) {
2478         // Shrink the first column to be able to show as much other
2479         // columns as possible
2480         qreal shrinkedFirstColumnWidth = firstColumnWidth - requiredWidth + availableWidth;
2481
2482         // TODO: A proper calculation of the minimum width depends on the implementation
2483         // of KItemListWidget. Probably a kind of minimum size-hint should be introduced
2484         // later.
2485         const qreal minWidth = qMin(firstColumnWidth, qreal(m_styleOption.iconSize * 2 + 200));
2486         if (shrinkedFirstColumnWidth < minWidth) {
2487             shrinkedFirstColumnWidth = minWidth;
2488         }
2489
2490         m_headerWidget->setColumnWidth(firstRole, shrinkedFirstColumnWidth);
2491         requiredWidth -= firstColumnWidth - shrinkedFirstColumnWidth;
2492     }
2493
2494     dynamicItemSize.rwidth() = qMax(requiredWidth, availableWidth);
2495
2496     m_layouter->setItemSize(dynamicItemSize);
2497
2498     // Update the role sizes for all visible widgets
2499     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2500     while (it.hasNext()) {
2501         it.next();
2502         updateWidgetColumnWidths(it.value());
2503     }
2504 }
2505
2506 qreal KItemListView::columnWidthsSum() const
2507 {
2508     qreal widthsSum = 0;
2509     for (const QByteArray &role : std::as_const(m_visibleRoles)) {
2510         widthsSum += m_headerWidget->columnWidth(role);
2511     }
2512     return widthsSum;
2513 }
2514
2515 QRectF KItemListView::headerBoundaries() const
2516 {
2517     return m_headerWidget->isVisible() ? m_headerWidget->geometry() : QRectF();
2518 }
2519
2520 bool KItemListView::changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const
2521 {
2522     if (newItemSize.isEmpty() || newGridSize.isEmpty()) {
2523         return false;
2524     }
2525
2526     if (m_layouter->scrollOrientation() == Qt::Vertical) {
2527         const qreal itemWidth = m_layouter->itemSize().width();
2528         if (itemWidth > 0) {
2529             const int newColumnCount = itemsPerSize(newGridSize.width(), newItemSize.width(), newItemMargin.width());
2530             if (m_model->count() > newColumnCount) {
2531                 const int oldColumnCount = itemsPerSize(m_layouter->size().width(), itemWidth, m_layouter->itemMargin().width());
2532                 return oldColumnCount != newColumnCount;
2533             }
2534         }
2535     } else {
2536         const qreal itemHeight = m_layouter->itemSize().height();
2537         if (itemHeight > 0) {
2538             const int newRowCount = itemsPerSize(newGridSize.height(), newItemSize.height(), newItemMargin.height());
2539             if (m_model->count() > newRowCount) {
2540                 const int oldRowCount = itemsPerSize(m_layouter->size().height(), itemHeight, m_layouter->itemMargin().height());
2541                 return oldRowCount != newRowCount;
2542             }
2543         }
2544     }
2545
2546     return false;
2547 }
2548
2549 bool KItemListView::animateChangedItemCount(int changedItemCount) const
2550 {
2551     if (m_itemSize.isEmpty()) {
2552         // We have only columns or only rows, but no grid: An animation is usually
2553         // welcome when inserting or removing items.
2554         return !supportsItemExpanding();
2555     }
2556
2557     if (m_layouter->size().isEmpty() || m_layouter->itemSize().isEmpty()) {
2558         return false;
2559     }
2560
2561     const int maximum = (scrollOrientation() == Qt::Vertical) ? m_layouter->size().width() / m_layouter->itemSize().width()
2562                                                               : m_layouter->size().height() / m_layouter->itemSize().height();
2563     // Only animate if up to 2/3 of a row or column are inserted or removed
2564     return changedItemCount <= maximum * 2 / 3;
2565 }
2566
2567 bool KItemListView::scrollBarRequired(const QSizeF &size) const
2568 {
2569     const QSizeF oldSize = m_layouter->size();
2570
2571     m_layouter->setSize(size);
2572     const qreal maxOffset = m_layouter->maximumScrollOffset();
2573     m_layouter->setSize(oldSize);
2574
2575     return m_layouter->scrollOrientation() == Qt::Vertical ? maxOffset > size.height() : maxOffset > size.width();
2576 }
2577
2578 int KItemListView::showDropIndicator(const QPointF &pos)
2579 {
2580     QHashIterator<int, KItemListWidget *> it(m_visibleItems);
2581     while (it.hasNext()) {
2582         it.next();
2583         const KItemListWidget *widget = it.value();
2584
2585         const QPointF mappedPos = widget->mapFromItem(this, pos);
2586         const QRectF rect = itemRect(widget->index());
2587         if (mappedPos.y() >= 0 && mappedPos.y() <= rect.height()) {
2588             if (m_model->supportsDropping(widget->index())) {
2589                 // Keep 30% of the rectangle as the gap instead of always having a fixed gap
2590                 const int gap = qMax(qreal(4.0), qreal(0.3) * rect.height());
2591                 if (mappedPos.y() >= gap && mappedPos.y() <= rect.height() - gap) {
2592                     return -1;
2593                 }
2594             }
2595
2596             const bool isAboveItem = (mappedPos.y() < rect.height() / 2);
2597             const qreal y = isAboveItem ? rect.top() : rect.bottom();
2598
2599             const QRectF draggingInsertIndicator(rect.left(), y, rect.width(), 1);
2600             if (m_dropIndicator != draggingInsertIndicator) {
2601                 m_dropIndicator = draggingInsertIndicator;
2602                 update();
2603             }
2604
2605             int index = widget->index();
2606             if (!isAboveItem) {
2607                 ++index;
2608             }
2609             return index;
2610         }
2611     }
2612
2613     const QRectF firstItemRect = itemRect(firstVisibleIndex());
2614     return (pos.y() <= firstItemRect.top()) ? 0 : -1;
2615 }
2616
2617 void KItemListView::hideDropIndicator()
2618 {
2619     if (!m_dropIndicator.isNull()) {
2620         m_dropIndicator = QRectF();
2621         update();
2622     }
2623 }
2624
2625 void KItemListView::updateGroupHeaderHeight()
2626 {
2627     qreal groupHeaderHeight = m_styleOption.fontMetrics.height();
2628     qreal groupHeaderMargin = 0;
2629
2630     if (scrollOrientation() == Qt::Horizontal) {
2631         // The vertical margin above and below the header should be
2632         // equal to the horizontal margin, not the vertical margin
2633         // from m_styleOption.
2634         groupHeaderHeight += 2 * m_styleOption.horizontalMargin;
2635         groupHeaderMargin = m_styleOption.horizontalMargin;
2636     } else if (m_itemSize.isEmpty()) {
2637         groupHeaderHeight += 4 * m_styleOption.padding;
2638         groupHeaderMargin = m_styleOption.iconSize / 2;
2639     } else {
2640         groupHeaderHeight += 2 * m_styleOption.padding + m_styleOption.verticalMargin;
2641         groupHeaderMargin = m_styleOption.iconSize / 4;
2642     }
2643     m_layouter->setGroupHeaderHeight(groupHeaderHeight);
2644     m_layouter->setGroupHeaderMargin(groupHeaderMargin);
2645
2646     updateVisibleGroupHeaders();
2647 }
2648
2649 void KItemListView::updateSiblingsInformation(int firstIndex, int lastIndex)
2650 {
2651     if (!supportsItemExpanding() || !m_model) {
2652         return;
2653     }
2654
2655     if (firstIndex < 0 || lastIndex < 0) {
2656         firstIndex = m_layouter->firstVisibleIndex();
2657         lastIndex = m_layouter->lastVisibleIndex();
2658     } else {
2659         const bool isRangeVisible = (firstIndex <= m_layouter->lastVisibleIndex() && lastIndex >= m_layouter->firstVisibleIndex());
2660         if (!isRangeVisible) {
2661             return;
2662         }
2663     }
2664
2665     int previousParents = 0;
2666     QBitArray previousSiblings;
2667
2668     // The rootIndex describes the first index where the siblings get
2669     // calculated from. For the calculation the upper most parent item
2670     // is required. For performance reasons it is checked first whether
2671     // the visible items before or after the current range already
2672     // contain a siblings information which can be used as base.
2673     int rootIndex = firstIndex;
2674
2675     KItemListWidget *widget = m_visibleItems.value(firstIndex - 1);
2676     if (!widget) {
2677         // There is no visible widget before the range, check whether there
2678         // is one after the range:
2679         widget = m_visibleItems.value(lastIndex + 1);
2680         if (widget) {
2681             // The sibling information of the widget may only be used if
2682             // all items of the range have the same number of parents.
2683             const int parents = m_model->expandedParentsCount(lastIndex + 1);
2684             for (int i = lastIndex; i >= firstIndex; --i) {
2685                 if (m_model->expandedParentsCount(i) != parents) {
2686                     widget = nullptr;
2687                     break;
2688                 }
2689             }
2690         }
2691     }
2692
2693     if (widget) {
2694         // Performance optimization: Use the sibling information of the visible
2695         // widget beside the given range.
2696         previousSiblings = widget->siblingsInformation();
2697         if (previousSiblings.isEmpty()) {
2698             return;
2699         }
2700         previousParents = previousSiblings.count() - 1;
2701         previousSiblings.truncate(previousParents);
2702     } else {
2703         // Potentially slow path: Go back to the upper most parent of firstIndex
2704         // to be able to calculate the initial value for the siblings.
2705         while (rootIndex > 0 && m_model->expandedParentsCount(rootIndex) > 0) {
2706             --rootIndex;
2707         }
2708     }
2709
2710     Q_ASSERT(previousParents >= 0);
2711     for (int i = rootIndex; i <= lastIndex; ++i) {
2712         // Update the parent-siblings in case if the current item represents
2713         // a child or an upper parent.
2714         const int currentParents = m_model->expandedParentsCount(i);
2715         Q_ASSERT(currentParents >= 0);
2716         if (previousParents < currentParents) {
2717             previousParents = currentParents;
2718             previousSiblings.resize(currentParents);
2719             previousSiblings.setBit(currentParents - 1, hasSiblingSuccessor(i - 1));
2720         } else if (previousParents > currentParents) {
2721             previousParents = currentParents;
2722             previousSiblings.truncate(currentParents);
2723         }
2724
2725         if (i >= firstIndex) {
2726             // The index represents a visible item. Apply the parent-siblings
2727             // and update the sibling of the current item.
2728             KItemListWidget *widget = m_visibleItems.value(i);
2729             if (!widget) {
2730                 continue;
2731             }
2732
2733             QBitArray siblings = previousSiblings;
2734             siblings.resize(siblings.count() + 1);
2735             siblings.setBit(siblings.count() - 1, hasSiblingSuccessor(i));
2736
2737             widget->setSiblingsInformation(siblings);
2738         }
2739     }
2740 }
2741
2742 bool KItemListView::hasSiblingSuccessor(int index) const
2743 {
2744     bool hasSuccessor = false;
2745     const int parentsCount = m_model->expandedParentsCount(index);
2746     int successorIndex = index + 1;
2747
2748     // Search the next sibling
2749     const int itemCount = m_model->count();
2750     while (successorIndex < itemCount) {
2751         const int currentParentsCount = m_model->expandedParentsCount(successorIndex);
2752         if (currentParentsCount == parentsCount) {
2753             hasSuccessor = true;
2754             break;
2755         } else if (currentParentsCount < parentsCount) {
2756             break;
2757         }
2758         ++successorIndex;
2759     }
2760
2761     if (m_grouped && hasSuccessor) {
2762         // If the sibling is part of another group, don't mark it as
2763         // successor as the group header is between the sibling connections.
2764         for (int i = index + 1; i <= successorIndex; ++i) {
2765             if (m_layouter->isFirstGroupItem(i)) {
2766                 hasSuccessor = false;
2767                 break;
2768             }
2769         }
2770     }
2771
2772     return hasSuccessor;
2773 }
2774
2775 void KItemListView::disconnectRoleEditingSignals(int index)
2776 {
2777     KStandardItemListWidget *widget = qobject_cast<KStandardItemListWidget *>(m_visibleItems.value(index));
2778     if (!widget) {
2779         return;
2780     }
2781
2782     disconnect(widget, &KItemListWidget::roleEditingCanceled, this, nullptr);
2783     disconnect(widget, &KItemListWidget::roleEditingFinished, this, nullptr);
2784     disconnect(this, &KItemListView::scrollOffsetChanged, widget, nullptr);
2785 }
2786
2787 int KItemListView::calculateAutoScrollingIncrement(int pos, int range, int oldInc)
2788 {
2789     int inc = 0;
2790
2791     const int minSpeed = 4;
2792     const int maxSpeed = 128;
2793     const int speedLimiter = 96;
2794     const int autoScrollBorder = 64;
2795
2796     // Limit the increment that is allowed to be added in comparison to 'oldInc'.
2797     // This assures that the autoscrolling speed grows gradually.
2798     const int incLimiter = 1;
2799
2800     if (pos < autoScrollBorder) {
2801         inc = -minSpeed + qAbs(pos - autoScrollBorder) * (pos - autoScrollBorder) / speedLimiter;
2802         inc = qMax(inc, -maxSpeed);
2803         inc = qMax(inc, oldInc - incLimiter);
2804     } else if (pos > range - autoScrollBorder) {
2805         inc = minSpeed + qAbs(pos - range + autoScrollBorder) * (pos - range + autoScrollBorder) / speedLimiter;
2806         inc = qMin(inc, maxSpeed);
2807         inc = qMin(inc, oldInc + incLimiter);
2808     }
2809
2810     return inc;
2811 }
2812
2813 int KItemListView::itemsPerSize(qreal size, qreal itemSize, qreal itemMargin)
2814 {
2815     const qreal availableSize = size - itemMargin;
2816     const int count = availableSize / (itemSize + itemMargin);
2817     return count;
2818 }
2819
2820 KItemListCreatorBase::~KItemListCreatorBase()
2821 {
2822     qDeleteAll(m_recycleableWidgets);
2823     qDeleteAll(m_createdWidgets);
2824 }
2825
2826 void KItemListCreatorBase::addCreatedWidget(QGraphicsWidget *widget)
2827 {
2828     m_createdWidgets.insert(widget);
2829 }
2830
2831 void KItemListCreatorBase::pushRecycleableWidget(QGraphicsWidget *widget)
2832 {
2833     Q_ASSERT(m_createdWidgets.contains(widget));
2834     m_createdWidgets.remove(widget);
2835
2836     if (m_recycleableWidgets.count() < 100) {
2837         m_recycleableWidgets.append(widget);
2838         widget->setVisible(false);
2839     } else {
2840         delete widget;
2841     }
2842 }
2843
2844 QGraphicsWidget *KItemListCreatorBase::popRecycleableWidget()
2845 {
2846     if (m_recycleableWidgets.isEmpty()) {
2847         return nullptr;
2848     }
2849
2850     QGraphicsWidget *widget = m_recycleableWidgets.takeLast();
2851     m_createdWidgets.insert(widget);
2852     return widget;
2853 }
2854
2855 KItemListWidgetCreatorBase::~KItemListWidgetCreatorBase()
2856 {
2857 }
2858
2859 void KItemListWidgetCreatorBase::recycle(KItemListWidget *widget)
2860 {
2861     widget->setParentItem(nullptr);
2862     widget->setOpacity(1.0);
2863     pushRecycleableWidget(widget);
2864 }
2865
2866 KItemListGroupHeaderCreatorBase::~KItemListGroupHeaderCreatorBase()
2867 {
2868 }
2869
2870 void KItemListGroupHeaderCreatorBase::recycle(KItemListGroupHeader *header)
2871 {
2872     header->setOpacity(1.0);
2873     pushRecycleableWidget(header);
2874 }
2875
2876 #include "moc_kitemlistview.cpp"